fix(sql): a two-table comma-join accepts a composite key - #161
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FiveTechSoft merged 1 commit intoAug 5, 2026
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`FROM a, b WHERE a.k1 = b.k1 AND a.k2 = b.k2` was rejected with "comma-join
supports a single equality join key; use INNER JOIN ... ON for composite
keys", while the identical predicate across THREE tables worked. The limit
was never about composite keys -- it was about which executor ran:
2 tables -> the equality is lowered into stmt.inner_join, a JoinClause
that holds exactly one left/right column pair
3+ tables -> the N-way executor, which reads the join equalities straight
from the WHERE and handles any number of them
So a two-table query hit a wall that a three-table one did not.
Do not lower a composite key and do not reject it: leave inner_join unset,
keep every equality in the WHERE, and let the N-way executor take the
statement. The gate that selected it moves from `>= 3 tables` to `>= 3
tables, or 2 tables with no inner_join`. A two-table join with a single key
still takes the simpler path, unchanged.
Reported from an ERP whose historical movement query joins moviminv and
conseinv on (ccodigocon, cdocumetra). Same failure on DBF/CDX and on
ADT/ADI -- it is a parser limit, independent of storage format.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
(cherry picked from commit 7346b95)
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SELECT ... FROM a, b WHERE a.k1 = b.k1 AND a.k2 = b.k2rejected the secondequality: the comma-join path only ever recognised a single-column join key, so
a composite key fell through as unsupported.
xBase applications join on composite keys routinely (ours does it on
document + line), and the same query written withINNER JOINalready worked— only the comma spelling was affected.
The fix does not lower a composite comma-join into the single-pair
JoinClause; it leavesinner_joinunset and lets the N-way executor take itfrom
from_tablesplus the WHERE equalities, which is the route three or moretables already take.
Tests
sql_parser_testextended with the composite comma-join form.Full suite green on this branch (1291 cases).