Question

Using Firebird, I want to combine the results of two queries using UNION ALL, then sort the resulting output on a given column.

(select C1, C2, C3 from T1) union all  (select C1, C2, C3 from T2) order by C3 

The parentheses came from valid syntax for other databases, and are needed to make sure the arguments to UNION ALL (an operation that’s defined to work on tables – i.e. an unordered set of records) don’t try to be ordered individually. However I couldn’t get this syntax to work in Firebird–how can it be done?

Answer 1

SELECT C1, C2, C3 FROM (     select C1, C2, C3 from T1     union all      select C1, C2, C3 from T2 ) order by C3