>>>I am sure this question has been asked million times but here is a million one:
>>>
>>>What SQL Select to use to find all records with duplicate entries? I am trying to add a UNIQUE constraint to a table but get error that duplicate rows exist.
>>>
>>>TIA.
>>
>>SQL Server 2005 and up
>>

>>select * from (select *, 
>>count(*) over (partition by GroupField) as cntDups from myTable) X where cntDups > 1

>>
>>SQL Server 2000 solution
>>

>>select T.* from myTable T 
>>inner join (select GroupField, count(*) as cntDups from myTable group by GroupField having count(*) > 1) X
>>on T.GroupField = X.GroupField

>
>What is "X" in your expression?

X is the alias for derived table. Funny, I explained it today once - it's because I'm lazy I use X.