问题
Is there a difference in the order of v1 and v2 in a BETWEEN query on SQL Server?
SELECT *
FROM table
WHERE col BETWEEN v1 AND v2
currently I don’t get any results if v1 is bigger than v2. Is this only syntactic sugar for
col >= v1 AND col <= v2
or does it really take all values between the two? on my current observations I guess it’s the first case.
回答1:
SQL Server 2008:
select 1
where 5 between 1 and 7
1 result
select 1
where 5 between 7 and 1
0 results
Based on these results, and the Postgre Docs I would hypothesize that the ANSI Standard is as follows (although I can't find that doc).
a between x and y
==
a >= x AND a <= y
UPDATE:
The SQL-92 spec says (quote):
"X BETWEEN Y AND Z" is equivalent to "X>=Y AND X<=Z"
回答2:
Yes! The order of the arguments in the BETWEEN predicate matter. And, yes, this is [mostly] syntactic sugar for the AND-ed comparison form.
The "mostly", above comes from the fact that while logically equivalent, the two expressions may (probably in the past...) receive a distinct query plan on some SQL servers. It is a safe guess that most servers, nowadays, provide an optimal handling of this type of filter, regardless of its form.
回答3:
Yes, you are right, is it only syntactic sugar for the construct you mentioned.
来源:https://stackoverflow.com/questions/1572840/sql-between-v1-and-v2