How to delete completely duplicate rows

Question

Say i have duplicate rows in my table and well my database design is of 3rd class :-

Insert Into tblProduct (ProductId,ProductName,Description,Category) Valu         


        

Answer 1

I had to do this a few weeks back... what version of SQL Server are you using? In SQL Server 2005 and up, you can use Row_Number as part of your select, and only select where Row_Number is 1. I forget the exact syntax, but it's well documented... something along the lines of:

Select t0.ProductID, 
       t0.ProductName, 
       t0.Description, 
       t0.Category
Into   tblCleanData
From   (
    Select ProductID, 
           ProductName, 
           Description, 
           Category, 
           Row_Number() Over (
               Partition By ProductID, 
                            ProductName, 
                            Description, 
                            Category
               Order By     ProductID,
                            ProductName,
                            Description,
                            Category
           ) As RowNumber
    From   MyTable
) As t0
Where t0.RowNumber = 1

Check out http://msdn.microsoft.com/en-us/library/ms186734.aspx, that should get you going in the right direction.