Question : SELECT THE FIRST DATA

Hi All,

Suppose I have below data :

Customer TrsNo  TrsDate        Qty
A             A1       01/01/2010   5
A             A2       01/31/2010   10
B             B1       01/02/2010   10
B             B2       01/05/2010   5
B             B3       01/29/2010   10

I want the result query :


Customer TrsNo  TrsDate        Qty
A             A1       01/01/2010   5
B             B1       01/02/2010   10

I want the first transaction date of each customer.

How could I do it?

Thank you.

Answer : SELECT THE FIRST DATA

Select Customer ,TrsNo  ,TrsDate        ,Qty
FROM (
     Select Customer ,TrsNo  ,TrsDate        ,Qty,
      rn = row_number() over (partition by Customer order by TrsDate ASC)
     from tbl
) SQ
Where rn=1