12 lines
231 B
MySQL
12 lines
231 B
MySQL
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use studb;
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-- 从多个表中查询数据时，如果存在相同的字段时，字段名前必须加表名
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select distinct t1.sid
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from t_stu t1, t_stu t2;
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where t1.sid > 2 and t2.sid > 3;
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/*
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对7案例的改写，去重
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*/
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