Question

I’m working on an SSIS package where I’m importing data from a CSV file into a SQL table.

The only field that I’m concern with is the Username. This Username must be unique. I don’t care whether first name or last name are the same or not.

In the package, I imported the data from file into a temp SQL table. And then I used SELECT DISTINCT to pick unique Username. And then insert into the destination table.

The problem is: When I do a SELECT DISTINCT Username, Firstname and Lastname FROM tempUsers.

It returns:

• JSmith, John, Smith
• JSmith, Joe, Smart
• MBopp, Mary, Boppins

But I want it to return:

• JSmith, John, Smith
• MBopp, Mary, Boppins

Answer 1

SELECT DISTINCT will select all distinct rows for each column you specify, so that’s not quite what you’re looking for.

If your flavor of SQL supports it, try GROUP BY with FIRST(), like the following. It will return the first record for each individual Username.

SELECT Username, FIRST(Firstname), FIRST(Lastname) FROM tempUsers GROUP BY Username 

If not, you have to do it the hard way using a row ID and sub-select:

SELECT Username, FIRST(Firstname), FIRST(Lastname) FROM tempUsers WHERE RowID IN (SELECT MIN(RowID)                 FROM tempUsers                 GROUP BY Username) 

** You shouldn’t use MIN with Firstname and Lastname, because you can’t guarantee they will come from the same row:

SELECT Username, MIN(Firstname), MIN(Lastname) FROM tempUsers GROUP BY Username