CODEWITHSUNDEEP
sql
Kei
Kei

Reputation: 771

SQL Multiple where on same field

I have this table

FieldA | FieldB
---------------
1        12
1        13
1        14
2        12
2        13
3        12
3        13

I want to obtain FieldA, where FieldB is equal to 12, but also equal to 13, but NOT equal to 14.

Expected output:

FieldA
-------
2
3

So far I've come to this:

SELECT FieldA FROM table
WHERE FieldB IN (12, 13) AND FieldB NOT IN (14)

But it doesn't seem to work, what am I missing ? Also, I would like to do it in a way that it is cross-database.

Upvotes: 2

Views: 152

Answers (1)

Gordon Linoff
Gordon Linoff

Reputation: 1270191

This is an example of a "set-within-sets" subqueries. I like to handle these with group by and having, because this is a very flexible approach. Based on the question in the text:

SELECT FieldA
FROM table
GROUP BY FieldA
HAVING SUM(CASE WHEN FieldB = 12 THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN FieldB = 14 THEN 1 ELSE 0 END) = 0;

Each condition in the having clause is checking for one of the conditions you care about. The first counts the number of rows where FieldB = 12 and the > 0 makes sure there is at least one. The second counts the number of rows where FieldB = 14. The = 0 makes sure there are none.

If, as suggested by your code, you want 12 and 13, then you can do:

SELECT FieldA
FROM table
GROUP BY FieldA
HAVING SUM(CASE WHEN FieldB = 12 THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN FieldB = 13 THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN FieldB = 14 THEN 1 ELSE 0 END) = 0;

And, if you want 12 or 13, you can do:

SELECT FieldA
FROM table
GROUP BY FieldA
HAVING SUM(CASE WHEN FieldB IN (12, 13) THEN 1 ELSE 0 END) > 0 AND
       SUM(CASE WHEN FieldB = 14 THEN 1 ELSE 0 END) = 0;

Upvotes: 3

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