Question

This may be a simple question but I can;t find the answer anywhere. Here is an abstracted version of the problem:

• I have a table ‘Data’ which has a column named ‘Key’ and a column named ‘Value’
• I have another table ‘Users’ which has columns named ‘ID’,’Key1′,’Key2′
• I want some sort of join which will give columns ‘ID’,’Value1′, and ‘Value2’ where Value1 is the value from Key1 and Value 2 is the value from Key2.

Answer 1

try

select u.id, d1.v as v1, d2.v as v2 from users u 
inner join data d1 on u.k1 = d1.k 
inner join data d2 on u.k2 = d2.k

you can check that it works on SQLFiddle