mysql sql 语句 查询重复数据 并删除重复数据 只保留一条

**#例1：根据手机号customer_id查询所有重复的数据**SELECT*FROMaad_apply_mainWHEREcustomer_id IN (SELECTcustomer_idFROMaad_apply_main GROUP BYcustomer_idHAVINGcount(customer_id) > 1) ORDER BY customer_id DESC ;#例2：根据手机号customer_id删除重复数据且只保留一条DELETEFROMaad_apply_mainWHEREstdmerno='***' ANDcustomer_id IN (SELECT*FROM(SELECTcustomer_idFROMaad_apply_main WHERE stdmerno='***' GROUP BY customer_idHAVING COUNT(customer_id) > 1) t1)AND apply_no NOT IN (SELECT*FROM(SELECTMIN(apply_no)FROMaad_apply_main WHERE stdmerno='***' GROUP BY customer_idHAVING COUNT(customer_id) > 1) t2)

**字段解释：**customer_id ： 根据此字段的重复来删除数据；stdmerno ： 根据此字段来约束需要去重复的对象apply_no ： 此字段为表的主键id字段

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