Question

Is there a way to do the following in Oracle:

SELECT * FROM   Tbl1 JOIN   Tbl2  USING  (col1) AND ON Tbl1.col2 = Tbl2.col3 

Answer 1

In standard SQL, you can use either USING or ON but not both. If you could use both, you’d omit the AND from your example.

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PMV commented (more accurately, asked – see also the poster’s answer):

My problem is I’ve got a bunch of tables, all with USING joins. If I try to add a table with different key names I get an ambiguous column error. Is there a graceful way to do this without converting all my joins to ON join?

Well, the best way to limit the damage imposed by the sadly misnamed columns is probably (and roughly – I’ve not debugged the SQL below):

SELECT *     FROM (SELECT *              FROM Tbl1                   JOIN Tbl2 USING (col1, col2, col3, col4)                   JOIN Tbl3 USING (col2, col4, col6, col23)                   JOIN Tbl4 USING (col2, col8, col3, col23)           ) AS SystematicNaming           JOIN Tbl5               ON  SystematicNaming.Col1 = Tbl5.Col1               AND SystematicNaming.ColA = Tbl5.PoorlyNamedColA               AND SystematicNaming.ColB = Tbl5.PoorlyNamedColB 

This preserves the convenient and systematic USING notation for as long as possible, while managing the join with Tbl5 in the way that it has to be managed given the non-uniform column names required to join with Tbl5.

I’m not sure that’s the best query layout, though I think it is reasonable.