一道面试题
表A中有字段B 其中有重复值(内容) 请计算出重复值(内容)是什么? 有几个?
------解决方案--------------------select B,count(*)
from A
group by B
having count(*)> 1
------解决方案--------------------select B,count(*)
from A
group by B
having count(*)> 1
------解决方案--------------------select B,
count(*) [个数]
from A
group by B
------解决方案--------------------1楼2 楼正解
------解决方案--------------------只有顶塞
------解决方案--------------------ding
------解决方案--------------------看来我不用怕sql面试了...
------解决方案--------------------select B,count(*)
from A
group by b
having count(b)> 1
------解决方案--------------------easy
------解决方案--------------------select B,count(*)
from A
group by B
having count(*)> 1
------解决方案--------------------pass
------解决方案--------------------select count(1),b from
from a
where exists(select * from a z where z.b = a.b)
group by b
这样也可以.
嘿嘿,面试的时候多写几种方法应该更好吧?