Question

First a query

SELECT * FROM mytable WHERE id='1'

Gives me a certain number of rows For example

id             |       context      |      cat     |    value
1                     Context 1            1           value 1
1                     Context 2            1           value 2
1                     Context 1            2           value 3
1                     Context 2            2           value 4

Now my problem instead of receiving the result in such way
I want it is this way instead

id      |   cat    |    Context 1     |  Context 2   
1            1           value 1          value 2       
1            2           value 3          value 4    

Answer 1

SELECT  md.id, md.cat, m1.value AS context1, m2.value AS context2
FROM    (
        SELECT  DISTINCT id, cat
        FROM    mytable
        WHERE   id = 1
        ) md
LEFT JOIN
        mytable m1
ON      m1.id = 1
        AND m1.cat = md.cat
        AND m1.context = 'context 1'
LEFT JOIN
        mytable m2
ON      m2.id = 1
        AND m2.cat = md.cat
        AND m2.context = 'context 2'