Re: SQL query...

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> if i have 5 tables and all of it has column X and i wanted to get unique
> values in column X for all tables..
> can i do it in one query?

Yes, you want to use UNION:

SELECT foo FROM table1
UNION
SELECT foo FROM table2
UNION
SELECT foo FROM table3
UNION
SELECT foo FROM table4
UNION
SELECT foo FROM table5;

This will by default remove all duplicate entries. Use UNION ALL to
see all entries, even duplicated ones. Note that UNION (and its
companions INTERSECT and EXPECT) all require that the tables have
the same number of columns, and that each column is of a compatible
type.


- --
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200302190926

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