是否在INSERT / UPDATE查询中存在多个MySQL子查询？
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2023-09-12
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我打算写以下查询:; G* U! {. ^, y& a
INSERT INTO summary (user_id,total_points,count_operations)SELECT 15 AS user_id, (SELECT SUM(points) FROM operations WHERE user_id = 15) AS total_points, (SELECT COUNT(*) FROM operations WHERE user_id = 15) AS count_operationsON DUPLICATE KEY UPDATEtotal_points = VALUES(total_points),count_operations = VALUES(count_operations);整个陈述是原子吗？也就是说，MySQL（带有MyISAM内部锁定引擎)operations表吗？9 F! A* c8 s+ m$ F: s
MySQL在某些情况下(如果在这个时间范围内添加新的操作)，是否有可能执行两个子查询顺序？total_points和count_operations不一致？
% o. D" m- D" T; r# S ; }* d. n$ t" i& L( o: l
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