mysql数据库删除重复数据
大家看一下我这个mysql数据库,我要删除这里面UserName and ContentText这两个字段的重复数据,不是单独删除一个字段里面的重复数据,是要对比UserName和ContentText这两个字段都一样的话删除,求删除语句怎么写呀???求高手帮忙...
我运行了这个怎么不对呢
语法明显不对,自己改改呗
[解决办法]
--删除重复数据
--方法
---用户删除大量数据重复,数据重复次数不多
begin
while((select count(1) from (select entry_id from ksd_entry group by entry_id having(COUNT(1))>1) as a
)>0)
begin
delete from ksd_entry where ksdid in (select min(entry_id) from ksd_entry group by entry_id having(COUNT(1))>1)
end
end
--方法1
------用于删除数据多次重复的数据
delete from ksd_entry where ksdid not in (select min(ksdid) from ksd_entry group by entry_id)
begin
while((select count(1) from (select UserName,ContentText from bigdata_comment group by UserName,ContentText having(COUNT(1))>1) as a
)>0)
begin
delete from bigdata_comment where ID in (select min(ID) from bigdata_comment group by UserName,ContentText having(COUNT(1))>1)
end
end