你应该这样,看看表中有没有重复的记录 select 产品名 from A group by having count(*)>1---如果查询有记录,则说明表A 中有重复的记录select 产品名 from B group by having count(*)>1---如果查询有记录,则说明表B 中有重复的记录
你应该这样,看看表中有没有重复的记录 select 产品名 from A group by 产品名 having count(*)>1---如果查询有记录,则说明表A 中有重复的记录select 产品名 from B group by 产品名 having count(*)>1---如果查询有记录,则说明表B 中有重复的记录
select * from B where 产品名 in ( select 产品名 from A )
select 产品名 from A group by having count(*)>1---如果查询有记录,则说明表A 中有重复的记录select 产品名 from B group by having count(*)>1---如果查询有记录,则说明表B 中有重复的记录
select 产品名 from A group by 产品名 having count(*)>1---如果查询有记录,则说明表A 中有重复的记录select 产品名 from B group by 产品名 having count(*)>1---如果查询有记录,则说明表B 中有重复的记录