Conditional subqueries with WHEN in CALL, EXISTS, COUNT and COLLECT

[imilinovic]

Release note

Added conditional subqueries: CALL (...) { WHEN p THEN body [WHEN ...] [ELSE body] } runs, per row, the first branch whose predicate is true. The same WHEN branches can form the body of EXISTS { }, COUNT { } and COLLECT { }.

Related product PRs

PRs from product repo this doc page is related to:

• feat(query): add conditional CALL subqueries memgraph#4984
• feat(query): allow WHEN branches in EXISTS, COUNT and COLLECT bodies memgraph#4985

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Project	Deployment	Actions	Updated
documentation	Ready	Preview	Oct 6, 2026 7:00pm UTC