Advanced-only `alter` entry word; ALTER TABLE <T> ADD COLUMN <col> <type>
[constraints] | DROP COLUMN <col> | RENAME COLUMN <old> TO <new> ->
SqlAlterTable, runtime-decomposed to the existing column executors
(do_add_column / do_drop_column / do_rename_column) — one undo step each,
no new worker layer. The COLUMN keyword is required (reserves bare
RENAME TO for 4h, ADD CONSTRAINT for 4g).
- ADD COLUMN takes NOT NULL / UNIQUE / DEFAULT / CHECK (no PK / inline
REFERENCES). do_add_column extended to consume the SQL raw-text
default_sql / check_sql (sql_expr is validate-only, the 4a.2
mechanism), reaching parity with CREATE TABLE's column constraints.
- Drop/rename column refuse a column any CHECK references — table-level
AND column-level (incl. a column's own self-check on rename) — the
4a.3 deferral, detected up-front by tokenizing the raw CHECK text
(skipping string literals). In the shared executors, so it guards both
the simple and SQL surfaces and fixes a latent rename-drift bug that
desynced the stored CHECK text and broke rebuild.
- SQL DROP COLUMN refuses an index-covered column (no --cascade SQL
spelling — matches SQLite + the simple default).
- The column executors and do_add_index gained an internal-__rdbms_*
guard (refuse as "no such table"), closing a pre-existing exposure on
both surfaces. (do_change_column_type / do_add_constraint /
do_add_relationship are a tracked follow-up.)
- `alter` is advanced-only; AlterTableAction::AddColumn is boxed
(clippy::large_enum_variant).
Docs: ADR-0035 status + §13 4e; ADR README; requirements.md Q1. Plan:
docs/plans/20260525-adr-0035-sql-ddl-4e.md.
Tests: 1854 passing / 0 failing / 0 skipped / 1 ignored; clippy clean.
Add foreign keys to advanced-mode SQL CREATE TABLE — the SQL spelling of
an ADR-0013 named relationship, created in the same transaction as the
table (one undo step).
- Grammar: inline `<col> … REFERENCES <parent>[(<col>)] [ON DELETE/UPDATE
…]` (a new column constraint) and table-level `[CONSTRAINT <name>]
FOREIGN KEY (<col>) REFERENCES …` (two new element branches — both
start on a concrete keyword, never a leading Optional, which would
abort the element Choice). Referential clauses reuse
shared::REFERENTIAL_CLAUSES.
- Builder: greedy FK-clause consumption (parens consumed internally so
they don't perturb the 4a.3 element-boundary depth tracker); inline FK
auto-named, table FK takes an optional CONSTRAINT name.
- Worker: do_create_table resolves + validates each FK before building
the DDL (self-ref validates against the in-statement columns/PK; bare
REFERENCES resolves to the parent's single-column PK, composite ->
error; PK-target + Type::fk_target_type compatibility), emits the
FOREIGN KEY clause identically to schema_to_ddl, and writes the
relationship metadata in the create transaction.
- Reuse: name/uniqueness/metadata-insert/type-compat factored into shared
helpers; do_add_relationship refactored to use them.
- FKs round-trip via the existing relationship plumbing (no new
persistence structures); describe surfaces the relationship.
Self-references and bare `REFERENCES <parent>` supported (user-confirmed).
Self-ref pre-submit indicator wrinkle deferred to 4i (tracked in ADR §13,
a code comment, and the plan).
DA/runda round added cross-cutting probes (FK survives the add-column
rebuild + a later rebuild_from_text; referential actions survive rebuild;
drop-child clears the relationship; drop-parent refused; bare self-ref
resolves to own PK) — all green, no fixes needed.
27 new tests (grammar/builder + Tier-3). Docs: ADR-0035 Status/§13,
README, requirements.md Q1.
Tests: 1795 passing, 0 failing, 1 ignored. Clippy clean.
Add table-level CHECK (e.g. `CREATE TABLE t (a int, b int, CHECK (a < b))`)
to advanced-mode SQL CREATE TABLE. Since SQLite exposes no PRAGMA for CHECK
constraints, a table-level CHECK cannot be read back from the engine and
becomes the source of truth in a new internal metadata table
`__rdbms_playground_table_checks (table_name, seq, check_expr)`.
- Grammar: new TABLE_CHECK element in ELEMENT_CHOICES.
- Builder: distinguishes a table-level CHECK from a column-level one by
element position (no column-def open in the element), using depth-aware
boundary tracking so a length-arg comma (`numeric(10,2)`) or a
table-PRIMARY KEY's inner comma is not mistaken for an element separator.
- Worker: do_create_table emits the CHECK clauses and writes the metadata
rows in its transaction; schema_to_ddl emits them identically on rebuild;
read_schema / read_schema_snapshot read them from the metadata table;
do_drop_table clears them.
- Persistence: TableSchema.check_constraints round-trips through project.yaml
(#[serde(default)], optional on read), mirroring unique_constraints.
- Composite UNIQUE deliberately stays PRAGMA-detected (engine-reportable,
unlike CHECK) — user-confirmed.
DA/runda round added cross-cutting tests and a forward-looking doc fix:
- table CHECK survives a rebuild triggered by `add column`, and a later
rebuild_from_text (the ADR-0013 rebuild primitive uses a raw DROP, so the
metadata rows keyed on the final name are preserved);
- dropping a column a table CHECK references fails cleanly (rollback, table
intact); detection is 4e, friendly wording is H1;
- dropping a table clears its CHECK metadata (no orphan rows on re-create);
- amended ADR §6 so 4h's RENAME also updates the new metadata table.
20 Tier-3 + 9 grammar/builder + 2 YAML tests. Docs: ADR-0035 Status/§13/§6,
README index, requirements.md Q1. Help/usage skeleton + describe display of
table-level constraints deferred to 4i (symmetric with 4a.2).
Tests: 1769 passing, 0 failing, 1 ignored. Clippy clean.
Advanced-mode SQL CREATE TABLE gains the constraints that need no new
internal table (the 4a.2 slice):
- Grammar (sql_create_table.rs): column-level DEFAULT/CHECK and
table-level UNIQUE(cols). DEFAULT is a literal or a *parenthesised*
expression (standard SQL) — a bare sql_expr greedily eats a following
NOT (NOT IN/LIKE/BETWEEN), breaking `DEFAULT 0 NOT NULL`; the parens
bound it. CHECK is paren-bounded already.
- Builder (ddl.rs): captures CHECK/DEFAULT raw SQL text by byte span
(sql_expr builds no AST) via capture_parenthesised_span /
capture_expr_span; routes single-column table UNIQUE into the
column's flag and composite UNIQUE into unique_constraints.
- Command/worker: ColumnSpec gains check_sql/default_sql (raw, preferred
over the typed Expr/Value); Command::SqlCreateTable + Request +
do_create_table gain unique_constraints; do_create_table emits raw
CHECK/DEFAULT and composite UNIQUE clauses.
- Round-trip (part D): ReadSchema/TableSchema gain unique_constraints;
read_schema detects composite UNIQUE via PRAGMA index_list origin 'u'
(single-column still folds to the column flag); schema_to_ddl emits
them; YAML RawTable/write_table round-trips (optional-on-read).
CHECK round-trips via __rdbms_playground_columns.check_expr, DEFAULT
via PRAGMA table_info — no new metadata table.
Table-level/multi-column CHECK remains 4a.3 (rejected "not yet
supported"); FK is 4b.
Tests: +7 builder (raw-text capture incl. the DEFAULT 0 NOT NULL
boundary the fix was found by; single/composite UNIQUE routing) and +4
Tier-3 (CHECK enforced, DEFAULT applied, composite UNIQUE enforced, and
all three survive a rebuild — the part-D round-trip). 1752 pass / 0 fail
/ 1 ignored; clippy clean. Plan + requirements.md updated.
Command + builder + worker for advanced-mode SQL CREATE TABLE
(sub-phase 4a), executed structurally through do_create_table:
- Command::SqlCreateTable + build_sql_create_table (ddl.rs): aliases via
from_sql_name (incl. double precision), column- and table-level
PRIMARY KEY, redundant-flag de-dup off a sole PK, IF NOT EXISTS.
Advanced REGISTRY entry on the shared `create` word (SQL-first, DSL
fallback); no-PK tables allowed (user-confirmed).
- Worker (db.rs): Request::SqlCreateTable + CreateOutcome + snapshot_then
(one undo step); IF NOT EXISTS no-op (no snapshot, but journalled, like
read-only commands). do_create_table inline-PK rule aligned with the
rebuild generator schema_to_ddl — no round-trip DDL drift; serial
autoincrement is independent of inline-PK (verified by round-trip
tests).
- Runtime/App: dispatch + CommandOutcome::SchemaSkipped +
AppEvent::DslCreateSkipped (structure + "already exists — skipped"
note). Friendly catalog keys added (engine-neutral).
DEFAULT/CHECK/table-level UNIQUE are absent from the 4a grammar (parse
error with usage skeleton; friendly message + support land in the 4a.2
constraint slice) — user-confirmed.
Tests: type resolver, grammar shape, builder (incl. the PK
detection bug they caught), and tests/sql_create_table.rs (worker
round-trip, serial autoincrement first/non-first across rebuild, IF NOT
EXISTS no-op + journalling, no-PK table, one undo step) + a replay-as-
write test. 1739 pass / 0 fail / 1 ignored; clippy clean.
Exit gate: ADR-0035 Proposed -> Accepted (validated end-to-end by 4a);
README + requirements.md Q1 updated.