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:5 r/ y r) |; r# k V3 {
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？
+ K2 _: x/ @: o9 h: v% _( WMySQL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？- i9 [7 X+ D6 x! A$ p2 a$ [2 ?
( u. M: B( d' R% x/ t4 N 解决方案: |
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