Question

I’ve read that logical operator AND has higher order of precedence than logical operator IN, but that doesn’t make sense since if that was true, then wouldn’t in the following statement the AND condition got evaluated before the IN condition ( thus before IN operator would be able to check whether Released field equals to any of the values specified within parentheses ?

SELECT Song, Released, Rating
FROM Songs
WHERE
Released IN (1967, 1977, 1987)
AND
SongName = ’WTTJ’

thanx

EDIT:

Egrunin and ig0774, I’ve checked it and unless I totally misunderstood your posts, it seems that

WHERE x > 0 AND x < 10 OR special_case = 1

is indeed the the same as

WHERE (x > 0 AND x < 10) OR special_case = 1

Namely, I did the the following three queries

SELECT * 
FROM Songs 
WHERE AvailableOnCD='N' AND Released > 2000 OR Released = 1989

SELECT *
FROM Songs
WHERE (AvailableOnCD='N' AND Released > 2000) OR Released = 1989

SELECT *
FROM Songs
WHERE AvailableOnCD='N' AND (Released > 2000 OR Released = 1989)

and as it turns out the following two queries produce the same result:

SELECT * 
FROM Songs 
WHERE AvailableOnCD='N' AND Released > 2000 OR Released = 1989

SELECT *
FROM Songs
WHERE (AvailableOnCD='N' AND Released > 2000) OR Released = 1989

while

SELECT *
FROM Songs
WHERE AvailableOnCD='N' AND (Released > 2000 OR Released = 1989)

gives a different result

Answer 1

Call me a n00b, but I always use parentheses in nontrivial compound conditions.

SELECT Song, Released, Rating
FROM Songs
WHERE
    (Released IN (1967, 1977, 1987))
AND
    SongName = ’WTTJ’

Edited (Corrected, the point remains the same.)

Just yesterday I got caught by this. Started with working code:

WHERE x < 0 or x > 10

Changed it in haste:

WHERE x < 0 or x > 10 AND special_case = 1

Broke, because this is what I wanted:

WHERE (x < 0 or x > 10) AND special_case = 1

But this is what I got:

WHERE x < 0 or (x > 10 AND special_case = 1)