WHEN NOT MATCHED BY TARGET – You should use this clause to insert new rows into the target table. The rows you insert into the table are those rows in the source table for which there are no matching rows in the target. WHEN NOT MATCHED BY SOURCE – If you want to delete a … Read more
This is usually caused by duplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times. You could quickly solve the problem by using a DISTINCT in your query (in fact, if ‘Y’ is a constant value you don’t even need … Read more
9.5 and newer: PostgreSQL 9.5 and newer support INSERT … ON CONFLICT (key) DO UPDATE (and ON CONFLICT (key) DO NOTHING), i.e. upsert. Comparison with ON DUPLICATE KEY UPDATE. Quick explanation. For usage see the manual – specifically the conflict_action clause in the syntax diagram, and the explanatory text. Unlike the solutions for 9.4 and … Read more