25 lines
640 B
SQL
25 lines
640 B
SQL
-- 清理 UserView 表中的重复记录
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-- 保留每对用户（UserId + TargetUserId）的最新一条记录
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-- 首先查看有多少重复记录
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SELECT UserId, TargetUserId, COUNT(*) as cnt
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FROM UserView
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GROUP BY UserId, TargetUserId
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HAVING COUNT(*) > 1;
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-- 删除重复记录，保留 Id 最大的那条（即最新的）
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DELETE FROM UserView
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WHERE Id NOT IN (
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SELECT MaxId FROM (
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SELECT MAX(Id) as MaxId
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FROM UserView
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GROUP BY UserId, TargetUserId
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) AS KeepRecords
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);
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-- 验证清理结果
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SELECT UserId, TargetUserId, COUNT(*) as cnt
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FROM UserView
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GROUP BY UserId, TargetUserId
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HAVING COUNT(*) > 1;
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