claude@clouddev1
12395a9a6c
`create table … with pk` now parses the column-constraint suffix; combined with the commit-1 db layer, a constrained table works end to end. - A shared constraint-suffix grammar fragment — `not null`, `unique`, `default <literal>` — sits after each column's `(type)` group; `build_create_table` walks the matched path per column and folds the constraints into `ColumnSpec`. - §9 redundancy check: every `with pk` column is a primary-key column, so `not null` (any) and `unique` (single-column PK) are rejected with a friendly error (`parse.custom.constraint_redundant_on_pk`). - `project.yaml` round-trip: `ColumnSchema` gains `not_null` / `default`; the YAML reader/writer and `build_read_schema` carry them, so `rebuild` / `export` / `import` preserve constraints. - ADR-0029 §2.1's example corrected — `create table` columns are all PK columns, so its suffix is for `default` / `check`; `docs/simple-mode-limitations.md` records that non-PK columns at create time need advanced mode. CHECK is deferred to the next commit. 1184 tests pass (+7); clippy clean.
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1.9 KiB
Simple-mode query limitations
Simple mode's DSL query surface is deliberately a subset of SQL. The DSL is a teaching on-ramp; advanced mode (raw SQL) is the full surface. This document is the running list of what a simple-mode query cannot express that advanced-mode SQL can.
It serves two audiences:
- Students — each entry is the seed of a short explanation of why the boundary exists and what to use instead (often: switch to advanced mode).
- Designers — the consolidated list feeds the future
Q4SQL-subset specification: the inverse view of what the supported subset deliberately leaves out.
The list grows as new simple-mode surface lands; each entry names the ADR that drew the boundary.
WHERE expressions (ADR-0026)
- Comparison operands are a column or a literal, not a
nested expression.
(a > b) = (c > d)— comparing two boolean sub-expressions — cannot be written. Parentheses group boolean sub-expressions, not comparison operands. - A bare column is not a boolean. A predicate always
has an operator: write
Active = true, notActive. - No arithmetic in expressions (
Price * 1.1). - No string concatenation.
- No scalar functions (
upper(Name),length(x), …). - No subqueries, and no
EXISTS.
Query shape (ADR-0026)
- No
ORDER BY.show data … limit <n>orders implicitly by the primary key; explicit ordering is not yet available. - No
LIMIT … OFFSET—limittakes a row count only.
Table creation (ADR-0029)
create tabledeclares only primary-key columns.create table T with pk …makes every listed column part of the primary key; there is no simple-mode syntax for a non-PK column in the same statement. Non-PK columns are added afterward withadd column. Creating a table with a mix of PK and non-PK columns in one statement needs advanced-modeCREATE TABLEsyntax.