INSERT/UPDATE/DELETE + value model + auto-show, with polish

DSL data operations (ADR-0014): - insert into T [(cols)] values (vals); short form insert into T (vals) omits values keyword for friendlier syntax. - update T set ... where col=val | --all-rows; delete from T where col=val | --all-rows; show data T. - Value AST (Number/Text/Bool/Null) with per-column-type validation in the executor: int/real/decimal/bool/date/ datetime/shortid each accept a documented literal shape and produce friendly format errors naming the column. - INSERT short form fills non-auto-generated columns in schema order; auto-fills serial via SQLite and shortid via the new generator (T2). - `add column [to table] T: c (type)` -- `to table` now optional. Database: - insert/update/delete via prepared statements with bound rusqlite::types::Value parameters. - InsertResult/UpdateResult/DeleteResult: writes return rows_affected plus the affected row(s) only (not the whole table), so users see exactly what changed. - INSERT shows the just-inserted row via last_insert_rowid. - UPDATE captures matching rowids up-front and fetches them post-update -- works even if the UPDATE changed the WHERE column. - DELETE reports per-relationship cascade effects by row- count diffing inbound child tables; UPDATE-side cascades are not yet detected (would need value diffing). - query_data formats cells (booleans true/false, NULLs as None). FK error enrichment: - Now lists both outbound (INSERT/UPDATE relevance) and inbound (DELETE/UPDATE on parent relevance) FKs from the metadata, so RESTRICT errors point at the children blocking the delete. - RelationshipSelector has a proper Display impl -- "no such relationship" reads cleanly. Relationship display: - target_table for AddRelationship/DropRelationship now returns the parent (1-side); structure rendering after add/drop shows that side's "Referenced by:" entry, matching the `from <Parent>` direction of the command. - [ok] summary uses display_subject so relationship commands show both endpoints (`from P.col to C.col`) rather than a single misleading table name. - Auto-name format `<Parent>_<pcol>_to_<Child>_<ccol>` (matches the from..to direction). Output rendering and scrolling: - Wrap-aware scroll: renderer reports both visible-row count and total wrapped-row count to App; scroll math caps against actual displayable rows. Long lines wrap; the bottom line is always reachable; PageUp/PageDown work correctly even after paging past the buffer top. - Multi-line messages (FK error enrichment, cascade summary) split into single-line OutputLines at creation time so wrap/scroll math agree. Runtime / events: - New AppEvent variants for Insert/Update/Delete success carrying typed result structs; DslDataSucceeded reserved for show-data queries. Docs: - ADR-0014 covers data-op grammar, value model, --all-rows safety, auto-show. - requirements.md: C5 done, T2 done, V2 partial (basic data view), V5 partial (show data added). New entries: C5a complex WHERE expressions; H1 progress note for FK enrichment; H1a (strong syntax-help in parse errors). Tests: 200 passing (183 lib + 17 integration), 0 skipped. Includes parser, type-validation, DB write/read, FK-failure enrichment, cascade-delete propagation, focused-auto-show behaviour, scroll-cap invariants. Clippy clean with nursery enabled.
2026-05-07 16:33:25 +00:00
parent 165068269b
commit 305e5083d5
16 changed files with 2638 additions and 109 deletions
@@ -138,6 +138,17 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"

+[[package]]
+name = "chacha20"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f8d983286843e49675a4b7a2d174efe136dc93a18d69130dd18198a6c167601"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.0",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "chumsky"
 version = "0.13.0"
@@ -195,6 +206,15 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "cpufeatures"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2a41393f66f16b0823bb79094d54ac5fbd34ab292ddafb9a0456ac9f87d201"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crossterm"
 version = "0.29.0"
@@ -518,6 +538,7 @@ dependencies = [
 "cfg-if",
 "libc",
 "r-efi 6.0.0",
+ "rand_core 0.10.1",
 "wasip2",
 "wasip3",
 ]
@@ -990,7 +1011,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3c80231409c20246a13fddb31776fb942c38553c51e871f8cbd687a4cfb5843d"
 dependencies = [
 "phf_shared",
- "rand",
+ "rand 0.8.6",
 ]

 [[package]]
@@ -1105,7 +1126,18 @@ version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5ca0ecfa931c29007047d1bc58e623ab12e5590e8c7cc53200d5202b69266d8a"
 dependencies = [
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2e8e8bcc7961af1fdac401278c6a831614941f6164ee3bf4ce61b7edb162207"
+dependencies = [
+ "chacha20",
+ "getrandom 0.4.2",
+ "rand_core 0.10.1",
 ]

 [[package]]
@@ -1114,6 +1146,12 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"

+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
 [[package]]
 name = "ratatui"
 version = "0.30.0"
@@ -1209,6 +1247,7 @@ dependencies = [
 "futures-util",
 "insta",
 "pretty_assertions",
+ "rand 0.10.1",
 "ratatui",
 "rusqlite",
 "thiserror 2.0.18",
@@ -1376,7 +1415,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
 "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.17",
 "digest",
 ]

@@ -13,6 +13,7 @@ anyhow = "1.0.102"
 chumsky = "0.13.0"
 crossterm = { version = "0.29.0", features = ["event-stream"] }
 futures-util = "0.3.32"
+rand = "0.10.1"
 ratatui = "0.30.0"
 rusqlite = { version = "0.39.0", features = ["bundled"] }
 thiserror = "2.0.18"
@@ -0,0 +1,172 @@
+# ADR-0014: Data operations, value literals, and the auto-show pattern
+
+## Status
+
+Accepted
+
+## Context
+
+Schema operations (ADRs 0002, 0005, 0011, 0013) gave us tables,
+columns, and relationships. Without INSERT / UPDATE / DELETE,
+foreign-key behaviour is observable but not demonstrable — a
+learner can't yet trigger a CASCADE or watch a constraint catch
+a bad write. C5 closes that gap.
+
+Several coupled questions:
+
+- **Value literals.** How does the user write `'2025-01-15'` for
+  a date column versus `42` for an int column? What gets
+  validated where?
+- **Safe defaults for destructive operations.** UPDATE and
+  DELETE without WHERE are classic foot-guns.
+- **Auto-generation of `shortid`.** T2 commits to client-side
+  generation at insert time, which now becomes load-bearing.
+- **FK error clarity.** SQLite reports `FOREIGN KEY constraint
+  failed` with no detail; pedagogically that's nearly useless.
+- **Showing data back to the user.** Without a `SELECT`-like
+  surface, the user has no way to see what changed.
+
+## Decision
+
+### Grammar
+
+```
+insert into <Table> [(<col>, <col>...)] values (<val>, <val>...)
+update <Table> set <col>=<val>[, <col>=<val>...] (where <col>=<val> | --all-rows)
+delete from <Table>                              (where <col>=<val> | --all-rows)
+show data <Table>
+```
+
+- **INSERT short form** (`insert into T values (...)`): values
+  apply to non-auto-generated columns in schema declaration
+  order. Serial columns are filled by SQLite; shortid columns
+  are auto-generated by the executor.
+- **INSERT long form** (with explicit column list): user
+  controls exactly which columns receive values; auto-generated
+  columns the user didn't list are still auto-filled.
+- **WHERE clause** is required for UPDATE and DELETE by default.
+  The `--all-rows` flag is the explicit opt-in to unfiltered
+  operations, following ADR-0009 (`--` reserved for opt-in
+  flags). Specifying both WHERE and `--all-rows` is a parse
+  error.
+- **WHERE this iteration** is exactly `<col>=<val>`. Richer
+  WHERE expressions (AND/OR/comparison/LIKE) are deferred — they
+  are tracked as a future iteration and are intended as the
+  bridge from DSL into real SQL fluency.
+- **`show data <Table>`** joins the V5 show-family (with
+  `show table <Name>`); auto-show after writes (below) means
+  most users won't need to call it explicitly.
+
+### Value literals
+
+The parser produces a small `Value` AST (`Number(String)`,
+`Text(String)`, `Bool(bool)`, `Null`). Per-column-type validation
+lives in the executor where the schema is known:
+
+| User-facing type | Accepted literal                                            |
+|------------------|-------------------------------------------------------------|
+| `text`           | single-quoted string `'hello'` (`''` escapes a quote)       |
+| `int`            | integer literal `42`, `-7`                                  |
+| `real`           | numeric literal `3.14`, `-0.5`                              |
+| `decimal`        | numeric literal; stored as text to preserve precision       |
+| `bool`           | `true` / `false`                                            |
+| `date`           | quoted `'YYYY-MM-DD'` (validated)                           |
+| `datetime`       | quoted `'YYYY-MM-DDTHH:MM:SS[.fff][Z|±HH:MM]'` (validated) |
+| `blob`           | DSL literal not supported this iteration                    |
+| `serial`         | normally omitted (auto-fill); explicit integer accepted     |
+| `shortid`        | normally omitted (auto-generated); explicit base58 10–12   |
+| `null`           | keyword `null`                                              |
+
+Validation produces friendly errors that name the column and
+expected shape — e.g. "column `Name` expects a quoted string for
+`text`, got number".
+
+### Auto-generation for `shortid`
+
+When an INSERT (in either form) does not provide a value for a
+`shortid` column, the executor calls the shortid generator and
+fills in a 10-character base58 value (no `0`/`O`/`I`/`l`).
+Explicit values are accepted but validated against the same
+alphabet and length range (10–12 chars). The `rand` crate is
+the source of randomness.
+
+### FK error enrichment
+
+SQLite reports `FOREIGN KEY constraint failed` without naming
+the offending constraint or value. The executor catches this
+class of error and appends the table's outbound relationships
+(via the metadata table from ADR-0013) to the message:
+
+```
+FOREIGN KEY constraint failed. Foreign keys on this table:
+  - Orders.CustId → Customers.id
+Check that each referenced value exists in the parent table.
+```
+
+Identifying the *exact* offending row is left to the H1 friendly
+error layer when that lands.
+
+### Auto-show after writes
+
+INSERT, UPDATE, and DELETE successfully completing fetch the
+target table's full data and emit a `DslDataSucceeded` event
+carrying both `rows_affected: Some(n)` and the data view. The
+App renders both. Users see the result immediately without
+needing a follow-up `show data` command.
+
+`show data <Table>` follows the same path with
+`rows_affected: None`.
+
+The auto-show convention is reserved for DSL data ops. When
+advanced-mode SQL lands (Q1), arbitrary `SELECT` statements may
+opt out — large result sets shouldn't be implicitly inserted into
+the session log.
+
+### Tabular rendering
+
+The data view is rendered as simple aligned-column text:
+
+```
+  id  | Name      | Email
+  ----+-----------+-----------------
+  1   | Alice     | a@b.com
+  2   | Bob       | (null)
+```
+
+Pretty box-drawing renderings (with truncation, scroll
+indicators, wide-table handling) are deferred to V4. NULL cells
+render as `(null)` to be explicitly visible; booleans render as
+`true`/`false` despite their integer storage.
+
+## Consequences
+
+- C5 is satisfied: INSERT/UPDATE/DELETE operate end-to-end with
+  validation, auto-generation, FK enforcement, and visible
+  feedback.
+- T2 is satisfied: shortid auto-generation runs on insert.
+- V2 partial: a usable tabular data view exists, with the
+  pretty-rendering iteration still ahead.
+- V5 partial: `show data` joins `show table` in the show family.
+- H1 partial: FK-failure messages are enriched without
+  introducing the full friendly-error layer.
+- The `--all-rows` opt-in convention is now established for
+  destructive-without-filter operations — future commands of the
+  same shape (`drop relationship --cascade`?) follow the
+  pattern.
+- The runtime's `CommandOutcome` enum is extended with a `Data`
+  variant. New data-emitting commands plug in there without
+  reshaping the dispatch.
+- Complex WHERE expressions (AND/OR/comparison/LIKE), bulk
+  INSERT, ORDER BY, LIMIT, JOIN, and SELECT in advanced mode are
+  explicitly out of scope for this iteration; richer DSL WHERE
+  is the bridge iteration toward Q1's full SQL handling.
+
+## See also
+
+- ADR-0005 (column types — value-literal mappings here mirror
+  the storage choices)
+- ADR-0009 (DSL command syntax conventions — `--` flag rule)
+- ADR-0011 (FK column type compatibility — used during the
+  validation that runs before writes)
+- ADR-0013 (relationships and rebuild-table — the FK metadata
+  used by the error-enrichment path)
@@ -19,3 +19,4 @@ This directory contains the project's ADRs, recorded per
 - [ADR-0011 — Foreign-key column type compatibility](0011-fk-column-type-compatibility.md)
 - [ADR-0012 — Internal metadata for user-facing column types](0012-internal-metadata-for-user-facing-types.md)
 - [ADR-0013 — Relationships, naming, and the rebuild-table strategy](0013-relationships-and-rebuild-table.md)
+- [ADR-0014 — Data operations, value literals, and the auto-show pattern](0014-data-operations-and-value-model.md)
@@ -132,7 +132,18 @@ against it.
 - [ ] **C4** Convenience: `create m:n relationship from <T1> to
  <T2>` produces an auto-named junction table the user can rename;
  pulls primary keys and FK definitions automatically.
- [ ] **C5** Data operations: insert / update / delete via DSL.
+- [x] **C5** Data operations: insert / update / delete via DSL.
+  *(ADR-0014. INSERT short and long forms, UPDATE/DELETE with
+  required WHERE plus `--all-rows` opt-in, `show data <T>`,
+  per-column-type value-literal validation, FK enforcement
+  with metadata-driven error enrichment, auto-show after
+  writes. Bulk insert, complex WHERE expressions, and SELECT
+  in advanced mode are explicitly tracked separately — see
+  C5a below.)*
+- [~] **C5a** Complex WHERE expressions (AND/OR/comparison
+  operators/LIKE) for UPDATE/DELETE/show-data filtering. Tracks
+  the natural progression from DSL into real SQL fluency that
+  motivates the playground; design and ADR pending.

 ## SQL handling

@@ -170,10 +181,11 @@ against it.
  `int`, `real`, `decimal`, `bool`, `date`, `datetime`, `blob`,
  `serial`, `shortid`. *(Mapping to SQLite STRICT covered by
  ADR-0005; FK target type rule by ADR-0011.)*
- [ ] **T2** `shortid` generation: base58, 10–12 characters,
+- [x] **T2** `shortid` generation: base58, 10–12 characters,
  omits ambiguous characters; generated client-side at insert.
-  *(Type exists; insert-time generation arrives with the data
-  insertion path.)*
+  *(Implemented per ADR-0014; auto-fills omitted shortid
+  columns and validates user-supplied values against the same
+  alphabet and length range.)*
 - [ ] **T3** Compound primary keys handled end-to-end (DSL,
  storage, display, FK reference).
  *(Progress: DSL grammar (`with pk a:int,b:int`), storage, and
@@ -193,6 +205,10 @@ against it.
  see V4 for the broader direction.)*
 - [ ] **V2** SQL query results render as a dynamic table view in
  the output pane, with multiple result tabs supported.
+  *(Progress: a basic aligned-column data view is rendered for
+  `show data` and after every write (ADR-0014). Pretty
+  box-drawing tables with truncation/scroll handling, plus
+  multi-tab support, remain in V4 territory.)*
 - [~] **V3** Full ER-diagram export (whole-database graph, viewed
  outside the TUI) — low priority; design and ADR pending.
 - [~] **V4** Output panel as a *scrollable per-session log* with
@@ -210,7 +226,7 @@ against it.
  styling, Markdown export, scroll indicator — remains pending.)*
 - [ ] **V5** `show <kind> [<name>]` family of commands for
  redisplaying schema info on demand. *(Progress: `show table
-  <name>` implemented and reuses the structure-render pipeline;
+  <name>` and `show data <Table>` implemented;
  `show tables`, `show relationships`, etc. pending.)*

 ## Project lifecycle (per ADR-0004)
@@ -281,6 +297,19 @@ against it.

 - [ ] **H1** Friendly error-rewriting layer translates SQLite
  error messages into learner-friendly equivalents.
+  *(Progress: foreign-key constraint failures are enriched
+  with both inbound and outbound relationship listings (so
+  RESTRICT errors point at the children that still reference
+  this table); full SQL → English translation pending.)*
+- [ ] **H1a** Strong syntax-help in parse errors. When the user
+  types something near-correct (e.g. `insert into T ('Oli')` —
+  forgotten `values`; or `update T set x=1` — missing WHERE),
+  the error should *name the missing keyword or clause* rather
+  than just point at the unexpected character. This is a
+  separate effort from H1 (which targets database errors); it
+  targets parser errors. Pending — multiple targeted fixes
+  shipping piecemeal so far (e.g. `values` becoming optional in
+  INSERT removes one such case).
 - [ ] **H2** `hint` provides contextual help for the current
  input or the most recent error.
 - [ ] **H3** `help` provides general reference and per-command
@@ -12,7 +12,9 @@ use crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyModifiers};
 use tracing::{trace, warn};

 use crate::action::Action;
-use crate::db::TableDescription;
+use crate::db::{
+    CascadeEffect, DataResult, DeleteResult, InsertResult, TableDescription, UpdateResult,
+};
 use crate::dsl::{Command, ParseError, parse_command};
 use crate::event::AppEvent;
 use crate::mode::Mode;
@@ -94,6 +96,11 @@ pub struct App {
    /// the visible window off the top of the buffer and shrink
    /// what the user sees.
    pub last_output_visible: usize,
+    /// The most recent total *wrapped* row count of the output
+    /// panel — counted in display rows after wrapping, not in
+    /// logical OutputLines. Required for accurate scroll capping
+    /// when long lines wrap to multiple display rows.
+    pub last_output_total_wrapped: usize,
 }

 const PAGE_SCROLL_LINES: usize = 5;
@@ -122,18 +129,22 @@ impl App {
            history_draft: None,
            output_scroll: 0,
            last_output_visible: 0,
+            last_output_total_wrapped: 0,
        }
    }

-    /// Called by the renderer with the current output-panel row
-    /// count so subsequent scroll input is capped against the
-    /// actual visible area, not the unrelated buffer length.
-    pub fn note_output_viewport(&mut self, visible_rows: usize) {
+    /// Called by the renderer with the current output-panel
+    /// dimensions (row count + total wrapped-row count for the
+    /// current buffer) so subsequent scroll input is capped
+    /// correctly. Without `total_wrapped`, scroll math would
+    /// incorrectly assume one logical line = one display row.
+    pub const fn note_output_viewport(&mut self, visible_rows: usize, total_wrapped_rows: usize) {
        self.last_output_visible = visible_rows;
+        self.last_output_total_wrapped = total_wrapped_rows;
        // If a previous PageUp drifted past the maximum useful
        // scroll (e.g. the user kept paging up past the top),
        // bring it back so the next PageDown is responsive.
-        let max = self.output.len().saturating_sub(visible_rows);
+        let max = total_wrapped_rows.saturating_sub(visible_rows);
        if self.output_scroll > max {
            self.output_scroll = max;
        }
@@ -166,6 +177,22 @@ impl App {
                self.handle_dsl_success(&command, description);
                Vec::new()
            }
+            AppEvent::DslDataSucceeded { command, data } => {
+                self.handle_dsl_query_success(&command, &data);
+                Vec::new()
+            }
+            AppEvent::DslInsertSucceeded { command, result } => {
+                self.handle_dsl_insert_success(&command, &result);
+                Vec::new()
+            }
+            AppEvent::DslUpdateSucceeded { command, result } => {
+                self.handle_dsl_update_success(&command, &result);
+                Vec::new()
+            }
+            AppEvent::DslDeleteSucceeded { command, result } => {
+                self.handle_dsl_delete_success(&command, &result);
+                Vec::new()
+            }
            AppEvent::DslFailed { command, error } => {
                self.handle_dsl_failure(&command, &error);
                Vec::new()
@@ -447,7 +474,7 @@ impl App {
    }

    fn handle_dsl_success(&mut self, command: &Command, description: Option<TableDescription>) {
-        let summary = format!("[ok] {} {}", command.verb(), command.target_table());
+        let summary = format!("[ok] {} {}", command.verb(), command.display_subject());
        self.note_system(summary);
        if let Some(desc) = description.as_ref() {
            self.note_system(format!("  {}", desc.name));
@@ -498,6 +525,50 @@ impl App {
        self.current_table = description;
    }

+    fn handle_dsl_query_success(&mut self, command: &Command, data: &DataResult) {
+        let summary = format!("[ok] {} {}", command.verb(), command.display_subject());
+        self.note_system(summary);
+        for line in render_data_view(data) {
+            self.note_system(line);
+        }
+    }
+
+    fn handle_dsl_insert_success(&mut self, command: &Command, result: &InsertResult) {
+        self.note_system(format!(
+            "[ok] {} {}",
+            command.verb(),
+            command.display_subject()
+        ));
+        self.note_system(format!("  {} row(s) inserted", result.rows_affected));
+        for line in render_data_view(&result.data) {
+            self.note_system(line);
+        }
+    }
+
+    fn handle_dsl_update_success(&mut self, command: &Command, result: &UpdateResult) {
+        self.note_system(format!(
+            "[ok] {} {}",
+            command.verb(),
+            command.display_subject()
+        ));
+        self.note_system(format!("  {} row(s) updated", result.rows_affected));
+        for line in render_data_view(&result.data) {
+            self.note_system(line);
+        }
+    }
+
+    fn handle_dsl_delete_success(&mut self, command: &Command, result: &DeleteResult) {
+        self.note_system(format!(
+            "[ok] {} {}",
+            command.verb(),
+            command.display_subject()
+        ));
+        self.note_system(format!("  {} row(s) deleted", result.rows_affected));
+        for effect in &result.cascade {
+            self.note_system(render_cascade_effect(effect));
+        }
+    }
+
    fn handle_dsl_failure(&mut self, command: &Command, error: &str) {
        warn!(verb = command.verb(), error, "dsl command failed");
        // Wrap the command portion in quotes so the message
@@ -506,7 +577,7 @@ impl App {
        self.note_error(format!(
            "\"{} {}\" failed: {error}",
            command.verb(),
-            command.target_table()
+            command.display_subject()
        ));
    }

@@ -529,19 +600,34 @@ impl App {
    }

    fn note_system(&mut self, text: impl Into<String>) {
-        self.push_output(OutputLine {
-            text: text.into(),
-            kind: OutputKind::System,
-            mode_at_submission: self.mode,
-        });
+        self.push_multiline(text.into(), OutputKind::System);
    }

    fn note_error(&mut self, text: impl Into<String>) {
-        self.push_output(OutputLine {
-            text: text.into(),
-            kind: OutputKind::Error,
-            mode_at_submission: self.mode,
-        });
+        self.push_multiline(text.into(), OutputKind::Error);
+    }
+
+    /// Push possibly-multi-line `text` as a sequence of single-line
+    /// `OutputLine`s. Keeping one display row per `OutputLine` is
+    /// what makes the scroll-position math (line count = display
+    /// rows) accurate; the renderer therefore truncates rather
+    /// than wraps long lines.
+    fn push_multiline(&mut self, text: String, kind: OutputKind) {
+        if text.is_empty() {
+            self.push_output(OutputLine {
+                text,
+                kind,
+                mode_at_submission: self.mode,
+            });
+            return;
+        }
+        for line in text.split('\n') {
+            self.push_output(OutputLine {
+                text: line.to_string(),
+                kind,
+                mode_at_submission: self.mode,
+            });
+        }
    }

    fn push_output(&mut self, line: OutputLine) {
@@ -556,13 +642,12 @@ impl App {
    }

    fn scroll_output_up(&mut self) {
-        // Cap at `len - visible` so the topmost visible chunk
-        // is the *first* `visible` lines of the buffer; going
-        // past that would shrink the view by sliding the window
-        // off the top.
+        // Cap at `total_wrapped - visible` (display rows, not
+        // logical lines) so the topmost visible chunk is the
+        // first `visible` rendered rows; going past that would
+        // shrink the view by sliding the window off the top.
        let max = self
-            .output
-            .len()
+            .last_output_total_wrapped
            .saturating_sub(self.last_output_visible.max(1));
        self.output_scroll = (self.output_scroll + PAGE_SCROLL_LINES).min(max);
    }
@@ -579,6 +664,94 @@ fn parse_error_message(err: &ParseError) -> String {
    }
 }

+fn render_cascade_effect(effect: &CascadeEffect) -> String {
+    use crate::dsl::ReferentialAction;
+    let what = match effect.action {
+        ReferentialAction::Cascade => "deleted",
+        ReferentialAction::SetNull => "had FK set to null",
+        ReferentialAction::Restrict | ReferentialAction::NoAction => "blocked",
+    };
+    format!(
+        "  related: {} row(s) {} in `{}` for relationship `{}` (on delete {})",
+        effect.rows_changed,
+        what,
+        effect.child_table,
+        effect.relationship_name,
+        effect.action,
+    )
+}
+
+/// Render a data result as a sequence of aligned-column text
+/// lines suitable for the output panel. Pretty box-drawing
+/// rendering is V4 territory; this version uses simple
+/// pipe-and-dash separators.
+fn render_data_view(data: &DataResult) -> Vec<String> {
+    let header = data.columns.clone();
+    let body: Vec<Vec<String>> = data
+        .rows
+        .iter()
+        .map(|row| {
+            row.iter()
+                .map(|cell| {
+                    cell.as_ref()
+                        .map_or_else(|| "(null)".to_string(), Clone::clone)
+                })
+                .collect()
+        })
+        .collect();
+
+    // Column widths = max(header, all cells) per column.
+    let mut widths: Vec<usize> = header.iter().map(String::len).collect();
+    for row in &body {
+        for (i, cell) in row.iter().enumerate() {
+            if i < widths.len() && cell.chars().count() > widths[i] {
+                widths[i] = cell.chars().count();
+            }
+        }
+    }
+
+    let mut out: Vec<String> = Vec::with_capacity(body.len() + 3);
+    out.push(format!("  {}", join_padded(&header, &widths)));
+    out.push(format!("  {}", separator_row(&widths)));
+    if body.is_empty() {
+        out.push("  (no rows)".to_string());
+    } else {
+        for row in &body {
+            out.push(format!("  {}", join_padded(row, &widths)));
+        }
+    }
+    out
+}
+
+fn join_padded(cells: &[String], widths: &[usize]) -> String {
+    let mut s = String::new();
+    for (i, cell) in cells.iter().enumerate() {
+        if i > 0 {
+            s.push_str(" | ");
+        }
+        let w = widths.get(i).copied().unwrap_or(0);
+        s.push_str(cell);
+        let pad = w.saturating_sub(cell.chars().count());
+        for _ in 0..pad {
+            s.push(' ');
+        }
+    }
+    s
+}
+
+fn separator_row(widths: &[usize]) -> String {
+    let mut s = String::new();
+    for (i, w) in widths.iter().enumerate() {
+        if i > 0 {
+            s.push_str("-+-");
+        }
+        for _ in 0..*w {
+            s.push('-');
+        }
+    }
+    s
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -1033,6 +1206,8 @@ mod tests {
        for i in 0..30 {
            app.note_system(format!("line{i}"));
        }
+        // Simulate a render establishing 10 visible / 30 wrapped.
+        app.note_output_viewport(10, 30);
        assert_eq!(app.output_scroll, 0);
        app.update(key(KeyCode::PageUp));
        assert_eq!(app.output_scroll, super::PAGE_SCROLL_LINES);
@@ -1044,6 +1219,7 @@ mod tests {
        for i in 0..30 {
            app.note_system(format!("line{i}"));
        }
+        app.note_output_viewport(10, 30);
        for _ in 0..3 {
            app.update(key(KeyCode::PageUp));
        }
@@ -1060,6 +1236,7 @@ mod tests {
        for i in 0..30 {
            app.note_system(format!("line{i}"));
        }
+        app.note_output_viewport(10, 30);
        app.update(key(KeyCode::PageUp));
        assert!(app.output_scroll > 0);
        // Any new output line snaps the scroll back to bottom so
@@ -1091,13 +1268,15 @@ mod tests {
        for i in 0..30 {
            app.note_system(format!("line{i}"));
        }
-        // Simulate a render reporting 10 visible rows.
-        app.note_output_viewport(10);
+        // Simulate a render reporting 10 visible rows over a
+        // 30-row wrapped buffer (every line fits in one row in
+        // this test).
+        app.note_output_viewport(10, 30);
        // Page up many times — past the maximum useful scroll.
        for _ in 0..20 {
            app.update(key(KeyCode::PageUp));
        }
-        // Cap should be at len - visible = 30 - 10 = 20.
+        // Cap should be at total_wrapped - visible = 30 - 10 = 20.
        assert_eq!(app.output_scroll, 20);
    }

@@ -1111,7 +1290,7 @@ mod tests {
            app.note_system(format!("line{i}"));
        }
        app.output_scroll = 100;
-        app.note_output_viewport(10);
+        app.note_output_viewport(10, 30);
        assert_eq!(app.output_scroll, 20);
    }

@@ -13,6 +13,7 @@

 use crate::dsl::action::ReferentialAction;
 use crate::dsl::types::Type;
+use crate::dsl::value::Value;

 /// A column at table-creation time: a name and a user-facing
 /// type. Constraints beyond `PRIMARY KEY` (NOT NULL, UNIQUE,
@@ -70,6 +71,38 @@ pub enum Command {
    ShowTable {
        name: String,
    },
+    /// Insert a single row. `columns` is `None` for the natural-
+    /// order short form (`insert into T values (...)`); the
+    /// executor fills in the column list by walking the schema.
+    Insert {
+        table: String,
+        columns: Option<Vec<String>>,
+        values: Vec<Value>,
+    },
+    /// Update rows matching the WHERE clause (or all rows when
+    /// `all_rows` is set, per ADR-0009 opt-in convention).
+    Update {
+        table: String,
+        assignments: Vec<(String, Value)>,
+        filter: RowFilter,
+    },
+    Delete {
+        table: String,
+        filter: RowFilter,
+    },
+    /// Render the rows of a table as a data view in the output.
+    ShowData {
+        name: String,
+    },
+}
+
+/// How an UPDATE / DELETE selects which rows to operate on.
+/// `Where` is the default safe form. `AllRows` is the explicit
+/// `--all-rows` flag opt-in for unfiltered operations.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum RowFilter {
+    Where { column: String, value: Value },
+    AllRows,
 }

 /// How a `drop relationship` command identifies the relationship
@@ -114,6 +147,10 @@ impl Command {
            Self::AddRelationship { .. } => "add relationship",
            Self::DropRelationship { .. } => "drop relationship",
            Self::ShowTable { .. } => "show table",
+            Self::Insert { .. } => "insert into",
+            Self::Update { .. } => "update",
+            Self::Delete { .. } => "delete from",
+            Self::ShowData { .. } => "show data",
        }
    }

@@ -126,16 +163,53 @@ impl Command {
        match self {
            Self::CreateTable { name, .. }
            | Self::DropTable { name }
-            | Self::ShowTable { name } => name,
-            Self::AddColumn { table, .. } => table,
-            Self::AddRelationship { child_table, .. } => child_table,
+            | Self::ShowTable { name }
+            | Self::ShowData { name } => name,
+            Self::AddColumn { table, .. }
+            | Self::Insert { table, .. }
+            | Self::Update { table, .. }
+            | Self::Delete { table, .. } => table,
+            // For relationships we focus on the parent (1-side):
+            // the structure rendering after add/drop shows that
+            // table's "Referenced by" entry, which is what the
+            // user looks at to confirm the relationship.
+            Self::AddRelationship { parent_table, .. } => parent_table,
            Self::DropRelationship { selector } => match selector {
-                RelationshipSelector::Endpoints { child_table, .. } => child_table,
-                // For a named drop we don't know the child table
-                // until the executor resolves it; the verb is
-                // still a sensible fallback for logging.
+                RelationshipSelector::Endpoints { parent_table, .. } => parent_table,
+                // For a named drop we don't know the parent table
+                // until the executor resolves it; the name itself
+                // is a sensible fallback for logging.
                RelationshipSelector::Named { name } => name,
            },
        }
    }
+
+    /// Human-readable subject for the `[ok] <verb> <subject>`
+    /// summary line. Most commands target a single table, but
+    /// relationship commands are better described by their
+    /// endpoints than by either side alone.
+    #[must_use]
+    pub fn display_subject(&self) -> String {
+        match self {
+            Self::AddRelationship {
+                parent_table,
+                parent_column,
+                child_table,
+                child_column,
+                ..
+            } => format!("from {parent_table}.{parent_column} to {child_table}.{child_column}"),
+            Self::DropRelationship { selector } => match selector {
+                RelationshipSelector::Named { name } => name.clone(),
+                RelationshipSelector::Endpoints {
+                    parent_table,
+                    parent_column,
+                    child_table,
+                    child_column,
+                } => format!(
+                    "from {parent_table}.{parent_column} to {child_table}.{child_column}"
+                ),
+            },
+            _ => self.target_table().to_string(),
+        }
+    }
 }
@@ -12,9 +12,12 @@
 pub mod action;
 pub mod command;
 pub mod parser;
+pub mod shortid;
 pub mod types;
+pub mod value;

 pub use action::ReferentialAction;
-pub use command::{ColumnSpec, Command, RelationshipSelector};
+pub use command::{ColumnSpec, Command, RelationshipSelector, RowFilter};
 pub use parser::{ParseError, parse_command};
 pub use types::Type;
+pub use value::Value;
@@ -14,8 +14,9 @@ use chumsky::error::RichReason;
 use chumsky::prelude::*;

 use crate::dsl::action::ReferentialAction;
-use crate::dsl::command::{ColumnSpec, Command, RelationshipSelector};
+use crate::dsl::command::{ColumnSpec, Command, RelationshipSelector, RowFilter};
 use crate::dsl::types::Type;
+use crate::dsl::value::Value;

 #[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
 pub enum ParseError {
@@ -128,10 +129,14 @@ fn command_parser<'a>()
        .ignore_then(identifier())
        .map(|name| Command::DropTable { name });

+    // `to table` is optional — both `add column to table T: c (text)`
+    // and `add column T: c (text)` parse identically.
+    let to_table_optional = keyword_ci("to")
+        .ignore_then(keyword_ci("table"))
+        .or_not();
    let add_column = keyword_ci("add")
        .ignore_then(keyword_ci("column"))
-        .ignore_then(keyword_ci("to"))
-        .ignore_then(keyword_ci("table"))
+        .ignore_then(to_table_optional)
        .ignore_then(identifier())
        .then_ignore(just(':').padded())
        .then(identifier())
@@ -143,23 +148,211 @@ fn command_parser<'a>()
    let add_relationship = add_relationship_parser();
    let drop_relationship = drop_relationship_parser();

+    let show_data = keyword_ci("show")
+        .ignore_then(keyword_ci("data"))
+        .ignore_then(identifier())
+        .map(|name| Command::ShowData { name });
+
    let show_table = keyword_ci("show")
        .ignore_then(keyword_ci("table"))
        .ignore_then(identifier())
        .map(|name| Command::ShowTable { name });

+    let insert_cmd = insert_parser();
+    let update_cmd = update_parser();
+    let delete_cmd = delete_parser();
+
    choice((
        create_table,
        drop_table,
        add_column,
        add_relationship,
        drop_relationship,
+        // Order: `show data` before `show table` because both
+        // start with `show` and the longer keyword is checked
+        // first via this ordering.
+        show_data,
        show_table,
+        insert_cmd,
+        update_cmd,
+        delete_cmd,
    ))
    .padded()
    .then_ignore(end())
 }

+/// INSERT, accepting three shapes:
+///   `insert into T (cols) values (vals)` — explicit columns
+///   `insert into T values (vals)`        — implicit column order
+///   `insert into T (vals)`               — short form, omits `values`
+///
+/// The short form is disambiguated from the column-list form by
+/// trying both alternatives in order; chumsky's `choice`
+/// backtracks, and only the all-literals form parses without
+/// `values`.
+fn insert_parser<'a>()
+-> impl Parser<'a, &'a str, Command, extra::Err<Rich<'a, char>>> + Clone {
+    let column_list = just('(')
+        .padded()
+        .ignore_then(
+            identifier()
+                .separated_by(just(',').padded())
+                .at_least(1)
+                .collect::<Vec<_>>(),
+        )
+        .then_ignore(just(')').padded());
+
+    let value_list = just('(')
+        .padded()
+        .ignore_then(
+            value_literal()
+                .separated_by(just(',').padded())
+                .at_least(1)
+                .collect::<Vec<_>>(),
+        )
+        .then_ignore(just(')').padded());
+
+    let with_columns_and_values = column_list
+        .clone()
+        .then_ignore(keyword_ci("values"))
+        .then(value_list.clone())
+        .map(|(cols, vals)| (Some(cols), vals));
+
+    let with_values_keyword_only = keyword_ci("values")
+        .ignore_then(value_list.clone())
+        .map(|vals| (None, vals));
+
+    let bare_value_list = value_list.map(|vals| (None, vals));
+
+    keyword_ci("insert")
+        .ignore_then(keyword_ci("into"))
+        .ignore_then(identifier())
+        .then(choice((
+            with_columns_and_values,
+            with_values_keyword_only,
+            bare_value_list,
+        )))
+        .map(|(table, (columns, values))| Command::Insert {
+            table,
+            columns,
+            values,
+        })
+}
+
+/// `update <T> set <col>=<val>[, <col>=<val>...] (where <col>=<val> | --all-rows)`.
+fn update_parser<'a>()
+-> impl Parser<'a, &'a str, Command, extra::Err<Rich<'a, char>>> + Clone {
+    let assignment = identifier()
+        .then_ignore(just('=').padded())
+        .then(value_literal());
+
+    let assignments = assignment
+        .separated_by(just(',').padded())
+        .at_least(1)
+        .collect::<Vec<_>>();
+
+    keyword_ci("update")
+        .ignore_then(identifier())
+        .then_ignore(keyword_ci("set"))
+        .then(assignments)
+        .then(filter_clause())
+        .map(|((table, assignments), filter)| Command::Update {
+            table,
+            assignments,
+            filter,
+        })
+}
+
+/// `delete from <T> (where <col>=<val> | --all-rows)`.
+fn delete_parser<'a>()
+-> impl Parser<'a, &'a str, Command, extra::Err<Rich<'a, char>>> + Clone {
+    keyword_ci("delete")
+        .ignore_then(keyword_ci("from"))
+        .ignore_then(identifier())
+        .then(filter_clause())
+        .map(|(table, filter)| Command::Delete { table, filter })
+}
+
+/// Parse the row-filter portion of UPDATE/DELETE: either
+/// `where <col>=<val>` or the `--all-rows` flag, with the two
+/// being mutually exclusive (specifying both is a parse error).
+fn filter_clause<'a>()
+-> impl Parser<'a, &'a str, RowFilter, extra::Err<Rich<'a, char>>> + Clone {
+    let where_clause = keyword_ci("where")
+        .ignore_then(identifier())
+        .then_ignore(just('=').padded())
+        .then(value_literal())
+        .map(|(column, value)| RowFilter::Where { column, value });
+
+    let all_rows = just("--all-rows").padded().to(RowFilter::AllRows);
+
+    where_clause.or(all_rows).labelled("where clause or --all-rows")
+}
+
+/// Parse a value literal: number, single-quoted string, `null`,
+/// `true`, or `false`.
+fn value_literal<'a>()
+-> impl Parser<'a, &'a str, Value, extra::Err<Rich<'a, char>>> + Clone {
+    choice((
+        keyword_ci("null").to(Value::Null),
+        keyword_ci("true").to(Value::Bool(true)),
+        keyword_ci("false").to(Value::Bool(false)),
+        number_literal(),
+        string_literal(),
+    ))
+    .padded()
+}
+
+fn number_literal<'a>()
+-> impl Parser<'a, &'a str, Value, extra::Err<Rich<'a, char>>> + Clone {
+    let sign = just('-').or_not();
+    let digits = any()
+        .filter(|c: &char| c.is_ascii_digit())
+        .repeated()
+        .at_least(1)
+        .collect::<String>();
+    let fraction = just('.')
+        .ignore_then(
+            any()
+                .filter(|c: &char| c.is_ascii_digit())
+                .repeated()
+                .at_least(1)
+                .collect::<String>(),
+        )
+        .or_not();
+    sign.then(digits)
+        .then(fraction)
+        .map(|((s, whole), frac)| {
+            let mut out = String::new();
+            if s.is_some() {
+                out.push('-');
+            }
+            out.push_str(&whole);
+            if let Some(f) = frac {
+                out.push('.');
+                out.push_str(&f);
+            }
+            Value::Number(out)
+        })
+}
+
+fn string_literal<'a>()
+-> impl Parser<'a, &'a str, Value, extra::Err<Rich<'a, char>>> + Clone {
+    // Single-quoted SQL string. `''` inside the literal escapes
+    // a literal single quote.
+    let body = just('\'')
+        .ignore_then(
+            choice((
+                just("''").to('\''),
+                any().filter(|c: &char| *c != '\''),
+            ))
+            .repeated()
+            .collect::<String>(),
+        )
+        .then_ignore(just('\''));
+    body.map(Value::Text)
+}
+
 /// `add 1:n relationship [<name>] from <P>.<col> to <C>.<col>
 ///   [on delete <action>] [on update <action>] [--create-fk]`.
 fn add_relationship_parser<'a>()
@@ -805,6 +998,188 @@ mod tests {
        assert!(matches!(e, ParseError::Invalid { .. }), "got {e:?}");
    }

+    #[test]
+    fn insert_with_explicit_column_list() {
+        assert_eq!(
+            ok("insert into Customers (Name, Email) values ('Alice', 'a@b.com')"),
+            Command::Insert {
+                table: "Customers".to_string(),
+                columns: Some(vec!["Name".to_string(), "Email".to_string()]),
+                values: vec![
+                    Value::Text("Alice".to_string()),
+                    Value::Text("a@b.com".to_string()),
+                ],
+            }
+        );
+    }
+
+    #[test]
+    fn insert_short_form_omitting_values_keyword() {
+        // User typed `insert into T (vals)` without `values`.
+        // Equivalent to `insert into T values (vals)`.
+        assert_eq!(
+            ok("insert into Customers ('Alice')"),
+            Command::Insert {
+                table: "Customers".to_string(),
+                columns: None,
+                values: vec![Value::Text("Alice".to_string())],
+            }
+        );
+    }
+
+    #[test]
+    fn insert_short_form_without_column_list() {
+        assert_eq!(
+            ok("insert into Customers values ('Alice', 'a@b.com')"),
+            Command::Insert {
+                table: "Customers".to_string(),
+                columns: None,
+                values: vec![
+                    Value::Text("Alice".to_string()),
+                    Value::Text("a@b.com".to_string()),
+                ],
+            }
+        );
+    }
+
+    #[test]
+    fn insert_accepts_mixed_value_kinds() {
+        assert_eq!(
+            ok("insert into T values (1, 3.14, 'hi', true, null)"),
+            Command::Insert {
+                table: "T".to_string(),
+                columns: None,
+                values: vec![
+                    Value::Number("1".to_string()),
+                    Value::Number("3.14".to_string()),
+                    Value::Text("hi".to_string()),
+                    Value::Bool(true),
+                    Value::Null,
+                ],
+            }
+        );
+    }
+
+    #[test]
+    fn insert_supports_negative_numbers() {
+        assert_eq!(
+            ok("insert into T values (-5, -3.14)"),
+            Command::Insert {
+                table: "T".to_string(),
+                columns: None,
+                values: vec![
+                    Value::Number("-5".to_string()),
+                    Value::Number("-3.14".to_string()),
+                ],
+            }
+        );
+    }
+
+    #[test]
+    fn string_literal_supports_escaped_single_quote() {
+        // SQL convention: '' inside a quoted string is a literal '.
+        assert_eq!(
+            ok("insert into T values ('don''t panic')"),
+            Command::Insert {
+                table: "T".to_string(),
+                columns: None,
+                values: vec![Value::Text("don't panic".to_string())],
+            }
+        );
+    }
+
+    #[test]
+    fn update_with_where() {
+        assert_eq!(
+            ok("update Customers set Name='Alice' where id=1"),
+            Command::Update {
+                table: "Customers".to_string(),
+                assignments: vec![("Name".to_string(), Value::Text("Alice".to_string()))],
+                filter: RowFilter::Where {
+                    column: "id".to_string(),
+                    value: Value::Number("1".to_string()),
+                },
+            }
+        );
+    }
+
+    #[test]
+    fn update_with_multiple_assignments() {
+        assert_eq!(
+            ok("update Customers set Name='Alice', Email='a@b.com' where id=1"),
+            Command::Update {
+                table: "Customers".to_string(),
+                assignments: vec![
+                    ("Name".to_string(), Value::Text("Alice".to_string())),
+                    ("Email".to_string(), Value::Text("a@b.com".to_string())),
+                ],
+                filter: RowFilter::Where {
+                    column: "id".to_string(),
+                    value: Value::Number("1".to_string()),
+                },
+            }
+        );
+    }
+
+    #[test]
+    fn update_with_all_rows_flag() {
+        assert_eq!(
+            ok("update Customers set Active=false --all-rows"),
+            Command::Update {
+                table: "Customers".to_string(),
+                assignments: vec![("Active".to_string(), Value::Bool(false))],
+                filter: RowFilter::AllRows,
+            }
+        );
+    }
+
+    #[test]
+    fn update_without_where_or_flag_errors() {
+        let e = err("update Customers set Active=false");
+        assert!(matches!(e, ParseError::Invalid { .. }), "got {e:?}");
+    }
+
+    #[test]
+    fn delete_with_where() {
+        assert_eq!(
+            ok("delete from Customers where id=1"),
+            Command::Delete {
+                table: "Customers".to_string(),
+                filter: RowFilter::Where {
+                    column: "id".to_string(),
+                    value: Value::Number("1".to_string()),
+                },
+            }
+        );
+    }
+
+    #[test]
+    fn delete_with_all_rows_flag() {
+        assert_eq!(
+            ok("delete from Customers --all-rows"),
+            Command::Delete {
+                table: "Customers".to_string(),
+                filter: RowFilter::AllRows,
+            }
+        );
+    }
+
+    #[test]
+    fn delete_without_where_or_flag_errors() {
+        let e = err("delete from Customers");
+        assert!(matches!(e, ParseError::Invalid { .. }), "got {e:?}");
+    }
+
+    #[test]
+    fn show_data_command() {
+        assert_eq!(
+            ok("show data Customers"),
+            Command::ShowData {
+                name: "Customers".to_string()
+            }
+        );
+    }
+
    #[test]
    fn drop_relationship_by_name() {
        assert_eq!(
@@ -0,0 +1,115 @@
+//! Shortid generation and validation.
+//!
+//! Per ADR-0005, the `shortid` user-facing type is a base58
+//! random identifier of 10–12 characters with no ambiguous
+//! glyphs (no `0`/`O`/`I`/`l`). The generator is small enough
+//! to live in the DSL crate alongside the type definition.
+
+use rand::RngExt;
+
+/// Base58 alphabet — Bitcoin-style. 0 / O / I / l are excluded
+/// because they are easily confused in print.
+const ALPHABET: &[u8; 58] =
+    b"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+
+const DEFAULT_LEN: usize = 10;
+
+/// Length bounds accepted on user-supplied shortid values.
+pub const MIN_LEN: usize = 10;
+pub const MAX_LEN: usize = 12;
+
+/// Generate a fresh shortid using thread-local RNG.
+#[must_use]
+pub fn generate() -> String {
+    generate_len(DEFAULT_LEN)
+}
+
+#[must_use]
+fn generate_len(len: usize) -> String {
+    let mut rng = rand::rng();
+    let mut out = String::with_capacity(len);
+    for _ in 0..len {
+        let idx = rng.random_range(0..ALPHABET.len());
+        out.push(ALPHABET[idx] as char);
+    }
+    out
+}
+
+/// Validate a user-supplied shortid value.
+pub fn validate(value: &str) -> Result<(), String> {
+    if value.len() < MIN_LEN || value.len() > MAX_LEN {
+        return Err(format!(
+            "shortid must be {MIN_LEN}–{MAX_LEN} characters; got {} character(s)",
+            value.chars().count()
+        ));
+    }
+    for c in value.chars() {
+        if !ALPHABET.contains(&(c as u8)) {
+            return Err(format!(
+                "shortid contains '{c}', which is not in the base58 alphabet \
+                 (no 0, O, I, or l; ASCII letters and digits otherwise)"
+            ));
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn generated_ids_have_default_length() {
+        let id = generate();
+        assert_eq!(id.len(), DEFAULT_LEN);
+    }
+
+    #[test]
+    fn generated_ids_use_only_base58_alphabet() {
+        for _ in 0..100 {
+            let id = generate();
+            for c in id.chars() {
+                assert!(
+                    ALPHABET.contains(&(c as u8)),
+                    "char {c:?} not in base58 alphabet"
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn generated_ids_are_not_all_identical() {
+        // Probabilistically extremely unlikely with a good RNG;
+        // catches a wholly broken generator (constant output).
+        let a = generate();
+        let b = generate();
+        let c = generate();
+        assert!(
+            a != b || b != c,
+            "all three generated ids were identical: {a}, {b}, {c}"
+        );
+    }
+
+    #[test]
+    fn validate_accepts_well_formed_values() {
+        assert!(validate("23456789Ab").is_ok()); // 10 chars
+        assert!(validate("23456789AbCD").is_ok()); // 12 chars
+    }
+
+    #[test]
+    fn validate_rejects_too_short_or_too_long() {
+        let err = validate("short").unwrap_err();
+        assert!(err.contains("characters"));
+        let err = validate("waytoolongafornow").unwrap_err();
+        assert!(err.contains("characters"));
+    }
+
+    #[test]
+    fn validate_rejects_ambiguous_glyphs() {
+        for bad in ["0aaaaaaaaa", "Oaaaaaaaaa", "Iaaaaaaaaa", "laaaaaaaaa"] {
+            let err = validate(bad).unwrap_err();
+            assert!(err.contains("base58"), "for {bad}: {err}");
+        }
+    }
+}
@@ -0,0 +1,390 @@
+//! User-facing value literals for INSERT / UPDATE / DELETE.
+//!
+//! The parser produces a small `Value` enum carrying just the
+//! shape of the literal as written. Per-column-type validation
+//! happens at execute time, where the schema is known and
+//! errors can name the offending column.
+
+use std::fmt;
+
+use crate::dsl::shortid;
+use crate::dsl::types::Type;
+
+/// A literal value as parsed from DSL input.
+///
+/// `Number` carries the original string so a literal like
+/// `3.14` can be stored as a decimal (TEXT) or a real (f64)
+/// depending on the destination column. The conversion happens
+/// in `bind_for_column`.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Value {
+    Number(String),
+    Text(String),
+    Bool(bool),
+    Null,
+}
+
+impl fmt::Display for Value {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Number(n) => f.write_str(n),
+            Self::Text(s) => write!(f, "'{}'", s.replace('\'', "''")),
+            Self::Bool(b) => f.write_str(if *b { "true" } else { "false" }),
+            Self::Null => f.write_str("null"),
+        }
+    }
+}
+
+/// Validated value ready to be bound as a parameter to a SQLite
+/// statement. Mirrors the storage choices made in ADR-0005.
+#[derive(Debug, Clone, PartialEq)]
+pub enum Bound {
+    Integer(i64),
+    Real(f64),
+    Text(String),
+    Null,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
+pub enum ValueError {
+    #[error("column `{column}` expects {expected_human}, got {got}")]
+    TypeMismatch {
+        column: String,
+        expected_human: String,
+        got: String,
+    },
+    #[error("column `{column}`: {message}")]
+    Format { column: String, message: String },
+}
+
+impl Value {
+    /// Validate `self` against `column`'s user-facing type and
+    /// produce a value ready for binding.
+    pub fn bind_for_column(&self, column: &str, ty: Type) -> Result<Bound, ValueError> {
+        if matches!(self, Self::Null) {
+            return Ok(Bound::Null);
+        }
+        match ty {
+            Type::Text | Type::ShortId => self.bind_text(column, ty),
+            Type::Int | Type::Serial => self.bind_int(column, ty),
+            Type::Real => self.bind_real(column),
+            Type::Decimal => self.bind_decimal(column),
+            Type::Bool => self.bind_bool(column),
+            Type::Date => self.bind_date(column),
+            Type::DateTime => self.bind_datetime(column),
+            Type::Blob => Err(ValueError::Format {
+                column: column.to_string(),
+                message: "literal `blob` values are not supported in DSL yet".to_string(),
+            }),
+        }
+    }
+
+    fn bind_text(&self, column: &str, ty: Type) -> Result<Bound, ValueError> {
+        match self {
+            Self::Text(s) => {
+                if ty == Type::ShortId {
+                    shortid::validate(s).map_err(|message| ValueError::Format {
+                        column: column.to_string(),
+                        message,
+                    })?;
+                }
+                Ok(Bound::Text(s.clone()))
+            }
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: format!("a quoted string for `{ty}`"),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_int(&self, column: &str, ty: Type) -> Result<Bound, ValueError> {
+        match self {
+            Self::Number(n) => n
+                .parse::<i64>()
+                .map(Bound::Integer)
+                .map_err(|_| ValueError::Format {
+                    column: column.to_string(),
+                    message: format!("`{n}` is not a valid {ty} (whole number expected)"),
+                }),
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: format!("a whole number for `{ty}`"),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_real(&self, column: &str) -> Result<Bound, ValueError> {
+        match self {
+            Self::Number(n) => n
+                .parse::<f64>()
+                .map(Bound::Real)
+                .map_err(|_| ValueError::Format {
+                    column: column.to_string(),
+                    message: format!("`{n}` is not a valid real number"),
+                }),
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: "a real number".to_string(),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_decimal(&self, column: &str) -> Result<Bound, ValueError> {
+        match self {
+            Self::Number(n) => {
+                // Validate parse-ability so a typo like `3..14` is rejected;
+                // we still store the original string to preserve precision.
+                if n.parse::<f64>().is_err() {
+                    return Err(ValueError::Format {
+                        column: column.to_string(),
+                        message: format!("`{n}` is not a valid decimal number"),
+                    });
+                }
+                Ok(Bound::Text(n.clone()))
+            }
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: "a decimal number".to_string(),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_bool(&self, column: &str) -> Result<Bound, ValueError> {
+        match self {
+            Self::Bool(b) => Ok(Bound::Integer(i64::from(*b))),
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: "`true` or `false`".to_string(),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_date(&self, column: &str) -> Result<Bound, ValueError> {
+        match self {
+            Self::Text(s) => {
+                validate_date(s).map_err(|message| ValueError::Format {
+                    column: column.to_string(),
+                    message,
+                })?;
+                Ok(Bound::Text(s.clone()))
+            }
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: "a quoted date 'YYYY-MM-DD'".to_string(),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    fn bind_datetime(&self, column: &str) -> Result<Bound, ValueError> {
+        match self {
+            Self::Text(s) => {
+                validate_datetime(s).map_err(|message| ValueError::Format {
+                    column: column.to_string(),
+                    message,
+                })?;
+                Ok(Bound::Text(s.clone()))
+            }
+            other => Err(ValueError::TypeMismatch {
+                column: column.to_string(),
+                expected_human: "a quoted datetime 'YYYY-MM-DDTHH:MM:SS'".to_string(),
+                got: other.kind_name().to_string(),
+            }),
+        }
+    }
+
+    const fn kind_name(&self) -> &'static str {
+        match self {
+            Self::Number(_) => "number",
+            Self::Text(_) => "string",
+            Self::Bool(_) => "boolean",
+            Self::Null => "null",
+        }
+    }
+}
+
+fn validate_date(s: &str) -> Result<(), String> {
+    // Expect YYYY-MM-DD: 10 chars, two dashes at fixed positions.
+    let bytes = s.as_bytes();
+    if bytes.len() != 10 || bytes[4] != b'-' || bytes[7] != b'-' {
+        return Err(format!(
+            "`{s}` is not a date in `YYYY-MM-DD` form"
+        ));
+    }
+    let year = parse_digits(&s[0..4]).ok_or_else(|| format!("`{s}`: invalid year"))?;
+    let month = parse_digits(&s[5..7]).ok_or_else(|| format!("`{s}`: invalid month"))?;
+    let day = parse_digits(&s[8..10]).ok_or_else(|| format!("`{s}`: invalid day"))?;
+    if !(1..=9999).contains(&year) {
+        return Err(format!("`{s}`: year {year} out of range 1..=9999"));
+    }
+    if !(1..=12).contains(&month) {
+        return Err(format!("`{s}`: month {month} out of range 1..=12"));
+    }
+    if !(1..=31).contains(&day) {
+        return Err(format!("`{s}`: day {day} out of range 1..=31"));
+    }
+    Ok(())
+}
+
+fn validate_datetime(s: &str) -> Result<(), String> {
+    // Minimum: YYYY-MM-DDTHH:MM:SS = 19 chars. Allow optional
+    // fractional seconds (.fff) and optional Z or ±HH:MM offset.
+    if s.len() < 19 {
+        return Err(format!(
+            "`{s}` is too short for a datetime in `YYYY-MM-DDTHH:MM:SS` form"
+        ));
+    }
+    let date_part = &s[0..10];
+    validate_date(date_part)?;
+    let bytes = s.as_bytes();
+    if bytes[10] != b'T' {
+        return Err(format!("`{s}`: missing `T` separator between date and time"));
+    }
+    if bytes[13] != b':' || bytes[16] != b':' {
+        return Err(format!("`{s}`: time portion must be `HH:MM:SS`"));
+    }
+    let hour = parse_digits(&s[11..13]).ok_or_else(|| format!("`{s}`: invalid hour"))?;
+    let min = parse_digits(&s[14..16]).ok_or_else(|| format!("`{s}`: invalid minute"))?;
+    let sec = parse_digits(&s[17..19]).ok_or_else(|| format!("`{s}`: invalid second"))?;
+    if hour > 23 {
+        return Err(format!("`{s}`: hour {hour} out of range 0..=23"));
+    }
+    if min > 59 {
+        return Err(format!("`{s}`: minute {min} out of range 0..=59"));
+    }
+    if sec > 60 {
+        return Err(format!(
+            "`{s}`: second {sec} out of range 0..=60 (60 allowed for leap second)"
+        ));
+    }
+    // Anything after position 19 is optional fractional / timezone
+    // suffix; we don't strictly validate it here (a future iteration
+    // can tighten this if needed).
+    Ok(())
+}
+
+fn parse_digits(s: &str) -> Option<u32> {
+    if s.is_empty() || !s.chars().all(|c| c.is_ascii_digit()) {
+        return None;
+    }
+    s.parse::<u32>().ok()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    fn n(s: &str) -> Value {
+        Value::Number(s.to_string())
+    }
+    fn t(s: &str) -> Value {
+        Value::Text(s.to_string())
+    }
+
+    #[test]
+    fn null_binds_to_null_for_any_type() {
+        for ty in Type::all() {
+            // Skip blob — null still works there too.
+            assert_eq!(Value::Null.bind_for_column("c", *ty).unwrap(), Bound::Null);
+        }
+    }
+
+    #[test]
+    fn integer_for_int_column() {
+        assert_eq!(n("42").bind_for_column("c", Type::Int).unwrap(), Bound::Integer(42));
+        assert_eq!(n("-7").bind_for_column("c", Type::Int).unwrap(), Bound::Integer(-7));
+    }
+
+    #[test]
+    fn non_integer_for_int_column_is_format_error() {
+        let err = n("3.14").bind_for_column("c", Type::Int).unwrap_err();
+        match err {
+            ValueError::Format { message, .. } => assert!(message.contains("whole number")),
+            other => panic!("unexpected: {other:?}"),
+        }
+    }
+
+    #[test]
+    fn string_for_int_column_is_type_mismatch() {
+        let err = t("hello").bind_for_column("c", Type::Int).unwrap_err();
+        assert!(matches!(err, ValueError::TypeMismatch { .. }));
+    }
+
+    #[test]
+    fn text_for_text_column() {
+        assert_eq!(
+            t("hi").bind_for_column("c", Type::Text).unwrap(),
+            Bound::Text("hi".to_string())
+        );
+    }
+
+    #[test]
+    fn shortid_validation_runs_on_text_for_shortid_column() {
+        let err = t("toolong_xyz_more").bind_for_column("c", Type::ShortId).unwrap_err();
+        assert!(matches!(err, ValueError::Format { .. }));
+
+        // Well-formed shortid binds fine.
+        assert_eq!(
+            t("23456789Ab").bind_for_column("c", Type::ShortId).unwrap(),
+            Bound::Text("23456789Ab".to_string())
+        );
+    }
+
+    #[test]
+    fn bool_for_bool_column_maps_to_zero_or_one() {
+        assert_eq!(Value::Bool(true).bind_for_column("c", Type::Bool).unwrap(), Bound::Integer(1));
+        assert_eq!(Value::Bool(false).bind_for_column("c", Type::Bool).unwrap(), Bound::Integer(0));
+    }
+
+    #[test]
+    fn date_iso_only() {
+        assert_eq!(
+            t("2025-01-15").bind_for_column("c", Type::Date).unwrap(),
+            Bound::Text("2025-01-15".to_string())
+        );
+        let err = t("2025/01/15").bind_for_column("c", Type::Date).unwrap_err();
+        assert!(matches!(err, ValueError::Format { .. }));
+    }
+
+    #[test]
+    fn date_range_check() {
+        let err = t("2025-13-01").bind_for_column("c", Type::Date).unwrap_err();
+        assert!(matches!(err, ValueError::Format { message, .. } if message.contains("month")));
+    }
+
+    #[test]
+    fn datetime_iso_only() {
+        assert_eq!(
+            t("2025-01-15T14:30:00")
+                .bind_for_column("c", Type::DateTime)
+                .unwrap(),
+            Bound::Text("2025-01-15T14:30:00".to_string())
+        );
+        let err = t("2025-01-15 14:30:00")
+            .bind_for_column("c", Type::DateTime)
+            .unwrap_err();
+        assert!(matches!(err, ValueError::Format { .. }));
+    }
+
+    #[test]
+    fn decimal_validates_numeric_string() {
+        assert_eq!(
+            n("3.14").bind_for_column("c", Type::Decimal).unwrap(),
+            Bound::Text("3.14".to_string())
+        );
+        let err = n("3..14").bind_for_column("c", Type::Decimal).unwrap_err();
+        assert!(matches!(err, ValueError::Format { .. }));
+    }
+
+    #[test]
+    fn blob_inserts_are_explicitly_unsupported_for_now() {
+        let err = t("0xdead").bind_for_column("c", Type::Blob).unwrap_err();
+        assert!(matches!(err, ValueError::Format { message, .. } if message.contains("blob")));
+    }
+}
@@ -7,7 +7,7 @@

 use crossterm::event::KeyEvent;

-use crate::db::TableDescription;
+use crate::db::{DataResult, DeleteResult, InsertResult, TableDescription, UpdateResult};
 use crate::dsl::Command;

 #[derive(Debug, Clone)]
@@ -25,6 +25,20 @@ pub enum AppEvent {
        command: Command,
        description: Option<TableDescription>,
    },
+    /// A `show data` query succeeded.
+    DslDataSucceeded { command: Command, data: DataResult },
+    DslInsertSucceeded {
+        command: Command,
+        result: InsertResult,
+    },
+    DslUpdateSucceeded {
+        command: Command,
+        result: UpdateResult,
+    },
+    DslDeleteSucceeded {
+        command: Command,
+        result: DeleteResult,
+    },
    /// A DSL command failed. `error` is already a friendly
    /// message produced via `DbError::friendly_message`.
    DslFailed {
@@ -26,7 +26,9 @@ use tracing::{debug, error, info, warn};

 use crate::action::Action;
 use crate::app::App;
-use crate::db::{Database, DbError, TableDescription};
+use crate::db::{
+    DataResult, Database, DbError, DeleteResult, InsertResult, TableDescription, UpdateResult,
+};
 use crate::dsl::Command;
 use crate::event::AppEvent;
 use crate::theme::Theme;
@@ -121,10 +123,26 @@ fn spawn_dsl_dispatch(
    tokio::spawn(async move {
        let outcome = execute_command(&database, command.clone()).await;
        let event = match outcome {
-            Ok(description) => AppEvent::DslSucceeded {
+            Ok(CommandOutcome::Schema(description)) => AppEvent::DslSucceeded {
                command: command.clone(),
                description,
            },
+            Ok(CommandOutcome::Query(data)) => AppEvent::DslDataSucceeded {
+                command: command.clone(),
+                data,
+            },
+            Ok(CommandOutcome::Insert(result)) => AppEvent::DslInsertSucceeded {
+                command: command.clone(),
+                result,
+            },
+            Ok(CommandOutcome::Update(result)) => AppEvent::DslUpdateSucceeded {
+                command: command.clone(),
+                result,
+            },
+            Ok(CommandOutcome::Delete(result)) => AppEvent::DslDeleteSucceeded {
+                command: command.clone(),
+                result,
+            },
            Err(error) => AppEvent::DslFailed {
                command: command.clone(),
                error,
@@ -141,15 +159,23 @@ fn spawn_dsl_dispatch(
            Ok(tables) => {
                let _ = event_tx.send(AppEvent::TablesRefreshed(tables)).await;
            }
-            Err(e) => warn!(error = %e, "post-DDL list_tables failed"),
+            Err(e) => warn!(error = %e, "post-list_tables failed"),
        }
    });
 }

+enum CommandOutcome {
+    Schema(Option<TableDescription>),
+    Query(DataResult),
+    Insert(InsertResult),
+    Update(UpdateResult),
+    Delete(DeleteResult),
+}
+
 async fn execute_command(
    database: &Database,
    command: Command,
-) -> Result<Option<TableDescription>, String> {
+) -> Result<CommandOutcome, String> {
    match command {
        Command::CreateTable {
            name,
@@ -158,17 +184,17 @@ async fn execute_command(
        } => database
            .create_table(name, columns, primary_key)
            .await
-            .map(Some)
+            .map(|d| CommandOutcome::Schema(Some(d)))
            .map_err(friendly),
        Command::DropTable { name } => database
            .drop_table(name)
            .await
-            .map(|()| None)
+            .map(|()| CommandOutcome::Schema(None))
            .map_err(friendly),
        Command::AddColumn { table, column, ty } => database
            .add_column(table, column, ty)
            .await
-            .map(Some)
+            .map(|d| CommandOutcome::Schema(Some(d)))
            .map_err(friendly),
        Command::AddRelationship {
            name,
@@ -191,16 +217,45 @@ async fn execute_command(
                create_fk,
            )
            .await
-            .map(Some)
+            .map(|d| CommandOutcome::Schema(Some(d)))
            .map_err(friendly),
        Command::DropRelationship { selector } => database
            .drop_relationship(selector)
            .await
+            .map(CommandOutcome::Schema)
            .map_err(friendly),
        Command::ShowTable { name } => database
            .describe_table(name)
            .await
-            .map(Some)
+            .map(|d| CommandOutcome::Schema(Some(d)))
+            .map_err(friendly),
+        Command::Insert {
+            table,
+            columns,
+            values,
+        } => database
+            .insert(table, columns, values)
+            .await
+            .map(CommandOutcome::Insert)
+            .map_err(friendly),
+        Command::Update {
+            table,
+            assignments,
+            filter,
+        } => database
+            .update(table, assignments, filter)
+            .await
+            .map(CommandOutcome::Update)
+            .map_err(friendly),
+        Command::Delete { table, filter } => database
+            .delete(table, filter)
+            .await
+            .map(CommandOutcome::Delete)
+            .map_err(friendly),
+        Command::ShowData { name } => database
+            .query_data(name)
+            .await
+            .map(CommandOutcome::Query)
            .map_err(friendly),
    }
 }
@@ -129,31 +129,73 @@ fn render_output_panel(app: &mut App, theme: &Theme, frame: &mut Frame<'_>, area
        vertical: 1,
    });

-    // Show a window of the buffer ending `output_scroll` lines
-    // above the most recent entry. With scroll == 0 the last
-    // line shown is the most recent; PageUp increases the
-    // scroll, revealing older lines. We report the visible row
-    // count back to App so input handling can cap scroll
-    // correctly between renders (otherwise scroll could drift
-    // past the top and slide the window off).
+    // Render every output line into a wrapped Paragraph and let
+    // ratatui handle the wrapping; we then use the wrapped row
+    // count to cap scroll correctly. Bottom-anchoring (most
+    // recent visible by default) is achieved by computing the
+    // scroll offset relative to the bottom of the wrapped view.
    let visible = inner.height as usize;
-    app.note_output_viewport(visible);
-    let total = app.output.len();
-    let max_scroll = total.saturating_sub(visible);
-    let effective_scroll = app.output_scroll.min(max_scroll);
-    let end = total - effective_scroll;
-    let start = end.saturating_sub(visible);
+
+    // Compute the total wrapped row count first, working from
+    // OutputLines directly (so the borrow ends before the
+    // mutable `note_output_viewport` call below).
+    let total_wrapped = approximate_wrapped_rows_from_output(&app.output, inner.width);
+    app.note_output_viewport(visible, total_wrapped);
+
    let lines: Vec<Line<'_>> = app
        .output
        .iter()
-        .skip(start)
-        .take(end - start)
        .map(|line| render_output_line(line, theme))
        .collect();
+    let paragraph = Paragraph::new(lines).wrap(Wrap { trim: false });
+
+    let max_scroll = total_wrapped.saturating_sub(visible);
+    let effective_scroll = app.output_scroll.min(max_scroll);
+    // Paragraph::scroll((y, _)) sets the topmost visible row.
+    // We want bottom-anchored: y = max_scroll - effective_scroll
+    // so scroll==0 shows the bottom and PageUp moves y down to
+    // reveal older content.
+    let scroll_y = max_scroll.saturating_sub(effective_scroll);
+    let scroll_y_u16 = u16::try_from(scroll_y).unwrap_or(u16::MAX);

    frame.render_widget(block, area);
-    let paragraph = Paragraph::new(lines).wrap(Wrap { trim: false });
-    frame.render_widget(paragraph, inner);
+    frame.render_widget(paragraph.scroll((scroll_y_u16, 0)), inner);
+}
+
+/// Approximate the number of display rows the output buffer
+/// will occupy after width-wrapping. Computed directly from
+/// `OutputLine`s (rather than the rendered `Line` objects) so
+/// the calculation can run before we hand `&mut App` to the
+/// scroll-cap update. Ratatui's exact `line_count` is gated
+/// behind an unstable feature; this character-based
+/// approximation is close enough for scroll capping — off-by-one
+/// at boundaries is acceptable.
+fn approximate_wrapped_rows_from_output(
+    output: &std::collections::VecDeque<OutputLine>,
+    width: u16,
+) -> usize {
+    if width == 0 {
+        return output.len();
+    }
+    let w = usize::from(width);
+    output
+        .iter()
+        .map(|line| {
+            // Tag width matches `render_output_line` exactly so
+            // the row count is right when the panel is too narrow
+            // for the natural line.
+            let tag_len = match line.kind {
+                OutputKind::Echo => match line.mode_at_submission {
+                    Mode::Simple => "[simple] ".len(),
+                    Mode::Advanced => "[advanced] ".len(),
+                },
+                OutputKind::System => "[system] ".len(),
+                OutputKind::Error => "[error]  ".len(),
+            };
+            let total = tag_len + line.text.chars().count();
+            if total == 0 { 1 } else { total.div_ceil(w) }
+        })
+        .sum()
 }

 fn render_output_line<'a>(line: &'a OutputLine, theme: &Theme) -> Line<'a> {
@@ -12,8 +12,10 @@ use ratatui::backend::TestBackend;

 use rdbms_playground::action::Action;
 use rdbms_playground::app::{App, OutputKind};
-use rdbms_playground::db::{ColumnDescription, RelationshipEnd, TableDescription};
-use rdbms_playground::dsl::{ColumnSpec, Command, ReferentialAction, Type};
+use rdbms_playground::db::{
+    ColumnDescription, DataResult, InsertResult, RelationshipEnd, TableDescription,
+};
+use rdbms_playground::dsl::{ColumnSpec, Command, ReferentialAction, RowFilter, Type, Value};
 use rdbms_playground::event::AppEvent;
 use rdbms_playground::mode::Mode;
 use rdbms_playground::theme::Theme;
@@ -357,7 +359,7 @@ fn drop_table_flow_clears_items_list() {
 }

 #[test]
-fn add_relationship_flow_shows_outbound_section() {
+fn add_relationship_flow_shows_parent_side_with_inbound_section() {
    let mut app = App::new();
    type_str(
        &mut app,
@@ -378,35 +380,28 @@ fn add_relationship_flow_shows_outbound_section() {
        })]
    );

-    // Simulate the runtime feeding back a description with the
-    // outbound relationship populated.
-    let orders = TableDescription {
-        name: "Orders".to_string(),
-        columns: vec![
-            ColumnDescription {
-                name: "id".to_string(),
-                user_type: Some(Type::Serial),
-                sqlite_type: "INTEGER".to_string(),
-                notnull: false,
-                primary_key: true,
-            },
-            ColumnDescription {
-                name: "CustId".to_string(),
-                user_type: Some(Type::Int),
-                sqlite_type: "INTEGER".to_string(),
-                notnull: false,
-                primary_key: false,
-            },
-        ],
-        outbound_relationships: vec![RelationshipEnd {
+    // The runtime now feeds back the parent (Customers) so the
+    // user sees the new relationship via the "Referenced by"
+    // section — same direction as the command's `from <Parent>`
+    // reading.
+    let customers = TableDescription {
+        name: "Customers".to_string(),
+        columns: vec![ColumnDescription {
+            name: "Id".to_string(),
+            user_type: Some(Type::Serial),
+            sqlite_type: "INTEGER".to_string(),
+            notnull: false,
+            primary_key: true,
+        }],
+        outbound_relationships: Vec::new(),
+        inbound_relationships: vec![RelationshipEnd {
            name: "Customers_Id_to_Orders_CustId".to_string(),
-            other_table: "Customers".to_string(),
-            other_column: "Id".to_string(),
-            local_column: "CustId".to_string(),
+            other_table: "Orders".to_string(),
+            other_column: "CustId".to_string(),
+            local_column: "Id".to_string(),
            on_delete: ReferentialAction::Cascade,
            on_update: ReferentialAction::NoAction,
        }],
-        inbound_relationships: Vec::new(),
    };
    app.update(AppEvent::DslSucceeded {
        command: Command::AddRelationship {
@@ -419,13 +414,19 @@ fn add_relationship_flow_shows_outbound_section() {
            on_update: ReferentialAction::NoAction,
            create_fk: false,
        },
-        description: Some(orders),
+        description: Some(customers),
    });

    let rendered = rendered_text(&mut app, &Theme::dark(), 80, 24);
-    assert!(rendered.contains("References:"), "{rendered}");
-    assert!(rendered.contains("CustId → Customers.Id"), "{rendered}");
+    assert!(rendered.contains("Referenced by:"), "{rendered}");
+    assert!(rendered.contains("Orders.CustId"), "{rendered}");
    assert!(rendered.contains("on delete cascade"), "{rendered}");
+    // The [ok] subject lists the endpoints. Long lines wrap in
+    // the panel, so we check the first half of the phrase only.
+    assert!(
+        rendered.contains("from Customers.Id"),
+        "{rendered}"
+    );
 }

 #[test]
@@ -463,6 +464,85 @@ fn add_relationship_flow_shows_inbound_section_on_parent() {
    assert!(rendered.contains("Orders.CustId → Id"), "{rendered}");
 }

+#[test]
+fn insert_flow_emits_action_and_renders_data() {
+    let mut app = App::new();
+
+    type_str(&mut app, "insert into Customers values ('Alice')");
+    let actions = submit(&mut app);
+    assert_eq!(
+        actions,
+        vec![Action::ExecuteDsl(Command::Insert {
+            table: "Customers".to_string(),
+            columns: None,
+            values: vec![Value::Text("Alice".to_string())],
+        })]
+    );
+
+    // Simulate the runtime feeding back an InsertResult.
+    let data = DataResult {
+        table_name: "Customers".to_string(),
+        columns: vec!["id".to_string(), "Name".to_string()],
+        rows: vec![vec![Some("1".to_string()), Some("Alice".to_string())]],
+    };
+    app.update(AppEvent::DslInsertSucceeded {
+        command: Command::Insert {
+            table: "Customers".to_string(),
+            columns: None,
+            values: vec![Value::Text("Alice".to_string())],
+        },
+        result: InsertResult {
+            rows_affected: 1,
+            data,
+        },
+    });
+    let rendered = rendered_text(&mut app, &Theme::dark(), 80, 24);
+    assert!(
+        rendered.contains("1 row(s) inserted"),
+        "should show row count:\n{rendered}"
+    );
+    assert!(
+        rendered.contains("Alice"),
+        "should auto-show new row:\n{rendered}"
+    );
+    assert!(
+        rendered.contains("id") && rendered.contains("Name"),
+        "should show column headers:\n{rendered}"
+    );
+}
+
+#[test]
+fn delete_with_all_rows_emits_correct_action() {
+    let mut app = App::new();
+    type_str(&mut app, "delete from Customers --all-rows");
+    let actions = submit(&mut app);
+    assert_eq!(
+        actions,
+        vec![Action::ExecuteDsl(Command::Delete {
+            table: "Customers".to_string(),
+            filter: RowFilter::AllRows,
+        })]
+    );
+}
+
+#[test]
+fn show_data_for_empty_table_renders_placeholder() {
+    let mut app = App::new();
+    let data = DataResult {
+        table_name: "Customers".to_string(),
+        columns: vec!["id".to_string(), "Name".to_string()],
+        rows: Vec::new(),
+    };
+    app.update(AppEvent::DslDataSucceeded {
+        command: Command::ShowData {
+            name: "Customers".to_string(),
+        },
+        data,
+    });
+    let rendered = rendered_text(&mut app, &Theme::dark(), 80, 24);
+    assert!(rendered.contains("(no rows)"), "{rendered}");
+}
+
 #[test]
 fn dsl_failure_shows_friendly_error_in_output() {
    let mut app = App::new();