CREATE TABLE Stock(item_id int UNIQUE, balance int); INSERT INTO Stock VALUES (10, 2200); INSERT INTO Stock VALUES (20, 1900);CREATE TABLE Buy(item_id int, volume int); INSERT INTO Buy values(10, 1000); INSERT INTO Buy values(30, 300);MERGE INTO Stock USING Buy ON Stock.item_id = Buy.item_id WHEN MATCHED THEN UPDATE SET balance = balance + Buy.volume WHEN NOT MATCHED THEN INSERT VALUES (Buy.item_id, Buy.volume);I am using Postgres 9.6.
ERROR MESSAGES! ALWAYS SHOW ERROR MESSAGES!!!
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Angular momentum makes the world go 'round.
Angular momentum makes the world go 'round.