Can you do a For Each Row loop using MySQL?

Question

My question is related to the answer found in this post by user Consultuning on Oct 22 \'09 at 18:31: mysql query to dynamically convert row data to columns

Answer 1

Not a for each exactly, but you can do nested SQL

SELECT 
    distinct a.ID, 
    a.col2, 
    (SELECT 
        SUM(b.size) 
    FROM 
        tableb b 
    WHERE 
        b.id = a.col3)
FROM
    tablea a