Question

I put together a sample scenario of my issue and I hope its enough for someone to point me in the right direction.

I have two tables

Products

Product Meta

I need a result set of the following

Answer 1

We’ve successfully used the following approach in the past…

SELECT [p].ProductID,        [p].Name,        MAX(CASE [m].MetaKey              WHEN 'A'                THEN [m].MetaValue            END) AS A,        MAX(CASE [m].MetaKey              WHEN 'B'                THEN [m].MetaValue            END) AS B,        MAX(CASE [m].MetaKey              WHEN 'C'                THEN [m].MetaValue            END) AS C FROM   Products [p]        INNER JOIN ProductMeta [m]          ON [p].ProductId = [m].ProductId GROUP  BY [p].ProductID,           [p].Name  

It can also be useful transposing aggregations with the use of…

SUM(CASE x WHEN 'y' THEN yVal ELSE 0 END) AS SUMYVal 

EDIT

Also worth noting this is using ANSI standard SQL and so it will work across platforms 🙂