Files
rdbms-playground/Cargo.toml
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claude@clouddev1 0c3847a5b9 db: column-origin type recovery in SELECT results (sub-phase 2f)
`Cargo.toml`: add `column_metadata` to rusqlite's feature list.
This pulls in the SQLite `SQLITE_ENABLE_COLUMN_METADATA`
compile flag and surfaces `sqlite3_column_table_name` /
`sqlite3_column_origin_name` on prepared statements via
rusqlite's `Statement::columns_with_metadata()`.

`do_run_select` in db.rs now calls a new
`resolve_select_column_types(conn, stmt)` helper after
`prepare`. The helper walks each result-column's origin
metadata; when both `table_name` and `origin_name` come back
populated (the result column traces back to a base-table
column), it looks up the playground type in
`__rdbms_playground_columns`. The per-column types thread
through to `format_cell(value, ty)` so the data-table
renderer (ADR-0016) gets the same per-type rendering it
applies to `show data` results.

Effect: ADR-0030 Phase-1 §4.5 (bool SELECT results render as
`0` / `1`) is lifted for any bare-column reference whose
origin the engine carries through — per ADR-0032 Amendment 1
(2026-05-20 empirical probe), that means all non-recursive
CTE bodies, scalar subqueries (aliased or not), derived
tables, set ops, and JOINs. Computed projections and
recursive-CTE result columns remain typeless (the engine
populates no origin), which the renderer handles via neutral
alignment.

The lookup is engine-driven verbatim — no grammar-side
structural classification (ADR-0032 Amendment 1 replaces
§12's original "structurally a single column reference" rule
with "trust column_table_name / column_origin_name").

Tests (3 new in `tests/sql_select.rs`, all green):

- `database_run_select_recovers_bool_column_type` — the
  Phase-1 §4.5 case: `SELECT Active FROM Products` returns
  `column_types = [Some(Bool)]` and rows render as `true` /
  `false`.
- `database_run_select_recovers_text_type_through_alias` —
  `SELECT Name AS n FROM Users` remaps the result column
  name to `n` but the origin metadata still resolves the
  playground type to `Some(Text)`.
- `database_run_select_computed_expression_stays_typeless`
  — `SELECT Score + 1 FROM T` keeps `column_types[0] =
  None`, the documented Amendment-1 exception.

The CTE pass-through, scalar subquery, set-op, and JOIN
cases all work for free given the empirical findings;
their behaviour is asserted by the Amendment-1 probe
results recorded in the ADR, so no per-case integration
tests are duplicated here.

Test totals: 1382 → 1385 passing (+3), 0 failed, 1 ignored.
Clippy clean.
2026-05-20 16:16:04 +00:00

46 lines
1.4 KiB
TOML

[package]
name = "rdbms-playground"
version = "0.1.0"
edition = "2024"
description = "A cross-platform TUI playground for learning relational databases."
license = "MIT OR Apache-2.0"
repository = "https://github.com/sturm/rdbms-playground"
readme = "README.md"
publish = false
[dependencies]
anyhow = "1.0.102"
base64 = "0.22.1"
crossterm = { version = "0.29.0", features = ["event-stream"] }
csv = "1.4.0"
directories = "6.0.0"
futures-util = "0.3.32"
gethostname = "1.1.0"
rand = "0.10.1"
ratatui = "0.30.0"
rusqlite = { version = "0.39.0", features = ["bundled", "column_metadata"] }
serde = { version = "1.0.228", features = ["derive"] }
serde_yml = "0.0.12"
sysinfo = { version = "0.39.0", default-features = false, features = ["system"] }
tokio = { version = "1.52.2", features = ["full"] }
tracing = "0.1.44"
tracing-subscriber = { version = "0.3.23", features = ["env-filter"] }
zip = { version = "5.1.1", default-features = false, features = ["deflate"] }
[dev-dependencies]
insta = { version = "1.47.2", features = ["yaml"] }
pretty_assertions = "1.4.1"
tempfile = "3.27.0"
[lints.rust]
unsafe_code = "forbid"
unreachable_pub = "warn"
[lints.clippy]
all = { level = "warn", priority = -1 }
nursery = { level = "warn", priority = -1 }
# Allow common false-positives that don't materially improve our code.
module_name_repetitions = "allow"
missing_errors_doc = "allow"
missing_panics_doc = "allow"