feat: pattern predicates in WHERE clause (openCypher 9)#32
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dylanbstorey merged 2 commits intomainfrom Mar 21, 2026
Merged
feat: pattern predicates in WHERE clause (openCypher 9)#32dylanbstorey merged 2 commits intomainfrom
dylanbstorey merged 2 commits intomainfrom
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March 20, 2026 22:51
Support bare relationship patterns as boolean expressions in WHERE clauses per the openCypher 9 PatternPredicate spec. Previously required explicit EXISTS() wrapper; now `WHERE NOT (n)-[:REL]->()` works directly as syntactic sugar for `WHERE NOT EXISTS((n)-[:REL]->())`. Also fixes pre-existing bug where EXISTS(pattern) ignored relationship direction — incoming (<-) and undirected (-) patterns now generate correct SQL.
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Summary
WHERE NOT (n)-[:REL]->()is syntactic sugar forWHERE NOT EXISTS((n)-[:REL]->()).EXISTS(pattern)always assumed outgoing direction — incoming (<-) and undirected (-) patterns now generate correct SQL.Closes GQLITE-T-0138.
Changes
cypher_gram.yexprproductions for 3- and 5-element pattern predicates;%expect4→9 (GLR-safe)transform_expr_predicate.c14_pattern_predicates.sqlTest plan
MATCH (n {entity_type: 'Note'}) WHERE NOT (n)-[:BELONGS_TO]->() ...now works