在行（val11，val21，val31），…，（val11，val21，val31）中选择其中（field1，field2，field3）的行

Question

I'm using mysql. I need to select rows from table (with fields id,field1,field2,field3 ) where (field1,field2,field3) in set of vectors (v11,v21,v31),(v12,v22,v32),...,(v1N,v2N,v3N) . Is it possible to do it with one query? If yes, what fields do I need to index to speed up the query? And is this query faster/slower then N serial simple select queries?

Thank you in advance!

Answer 1

You can do a multi-column IN comparison like so:

SELECT id,
       field1,
       field2,
       field3
FROM   tbl
WHERE  (field1,field2,field3) IN (
           (v11,v21,v31),
           (v12,v22,v32),
           (v1n,v2n,v3n)
       )

And it's essentially saying:

Where

(field1 = v11 AND field2 = v21 AND field3 = v31) OR
(field1 = v12 AND field2 = v22 AND field3 = v32) OR
...                                              OR
...