Question

I’m trying to create a query and need to join against something that I can define values in without creating a table.

I’ll attempt to describe what I’m trying to do:

table1
-------
fieldA 

is joined on fieldA with

table2 
-------
(titles for FK in table 1)

• Table1 has values outside of what exists in table2
• I want to add an additional ‘table’ to be unioned with table2 and then joined with table 1

Thanks

Answer 1

Sure, you can use a UNION ALL inside a subselect and join with the result of that. Something like this might do the trick:

SELECT *
FROM table1 T1
JOIN (
    SELECT titles, stuff 
    FROM table2
    UNION ALL
    SELECT 'foo' AS titles, 'foostuff' AS stuff
    UNION ALL
    SELECT 'bar' AS titles, 'barstuff' AS stuff
) T2
ON T1.id = T2.titles

Note that the columns in the UNION ALL must be of the same type and in the same order. The column names don’t have to match though.