查找字段大于MySQL集合中所有值的记录

Question

I have a table T1 with columns C1, C2, C3, C4 and T2 with columns C1 and D1 . I'd like to select all rows in T1 where appropriate row in T2 has D1 greater than C2 , C3 and C4 .

I tried something like this

SELECT C1,C2,C3,C4 FROM T1
WHERE (SELECT D1 FROM T2 WHERE C1=T1.C1)>(C2,C3,C4)

and this

SELECT C1,C2,C3,C4 FROM T1
WHERE (SELECT D1 FROM T2 WHERE C1=T1.C1)>MAX(C2,C3,C4)

but what I get is an error in syntax. I could write WHERE clause like this:

WHERE (SELECT D1 FROM T2 WHERE C1=T1.C1)> C2
 AND  (SELECT D1 FROM T2 WHERE C1=T1.C1)> C3
 AND  (SELECT D1 FROM T2 WHERE C1=T1.C1)> C4

However, running the same subquery 3 times is unnecessary for it always returns the same result.

Could anyone help? :)

Answer 1

You want the GREATEST() function, which allows multiple arguments. MAX() accepts only a single argument, and is intended for aggregate operations

SELECT *
FROM T1
...
WHERE T2.D1 > GREATEST(C1,C2,C3,C4)

If it helps, MAX() works "vertically", on a single field in a result set. GREATEST() works "horizontally", and operates within a single record.

Answer 2

Also if I understand correctly, your key is C1... you need to join your tables properly..

SELECT T1.*
FROM T1
LEFT JOIN T2 USING (C1)
WHERE D1 > GREATEST(C2,C3,C4)

Answer 3

I put together a little SQL Fiddle for you here and tried to replicate my understanding of what you are asking.

Here is the query I used:

SELECT one.* FROM one, two
WHERE (two.frags > one.size)
  AND (two.frags > one.weight)
  AND (two.frags > one.height)