Re: SELECT from two tables with different field names?

On Dec 13, 2011 4:34 PM, "Thomas Kellerer" <spam_eater(at)gmx(dot)net> wrote:
>
> Pandu Poluan, 13.12.2011 04:40:
>
>> > Yes a UNION should do (actually a UNION ALL as it will not try to
remove duplicates which makes the query faster)
>> >
>> > select *
>> > from (
>> > select emp_id, fullname
>> > from table_one
>> >
>> > union all
>> >
>> > select employee_id,
>> > first_name||' '||last_name
>> > from table_two
>> > ) t
>> > where emp_id = 1
>> >
>>
>> Thank you! I can see how UNION ALL will speed the query.
>>
>> But, shouldn't I put the WHERE clause in the inner SELECTs?
>
>
> I thought your goal was to just have a single condition. But if you can
push that into the union that would be more efficient.
>

Well, I need a single query not a single condition, but thanks for
confirming :-)

Rgds,