以下sql是a,b两张表通过关联条件id修改a表值,如果b表有重复数据记录,选第一条更新,红色条件为附加限制条件,具体视情况而定: UPDATE a SETname = b.fname,pwd = b.lnameFROM bWHERE a.id = b.id AND a.id in (2,3) 以下sql为查询单表中重复记录: select * from b t1 where t1.fname in (select t2.fname from b t2 group by t2.fname ha
查找所有重复标题的记录:SELECT *FROM t_info aWHERE ((SELECT COUNT(*)FROM t_infoWHERE Title = a.Title) > 1)ORDER BY Title DESC一.查找重复记录1.查找全部重复记录Select * From 表 Where 重复字段 In (Select 重复字段 From 表 Group By 重复字段 Having Count(*)>1)2.过滤重复记录(只显示一条)Select * From HZT Whe
查找所有重复标题的记录:SELECT * FROM t_info a WHERE ((SELECT COUNT(*) FROM t_info WHERE Title = a.Title) > 1) ORDER BY Title DESC一.查找重复记录1.查找全部重复记录Select * From 表 Where 重复字段 In (Select 重复字段 From 表 Group By 重复字段 Having Count(*)>1)2.过滤重复记录(只显示一条)Select * From HZ