Multiple MySql WHERE Between Clauses

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暗喜
暗喜 2021-01-01 05:05

Newbie MySql programmer thanks for the patience.

Im trying to track an Id number in a table where 3 different conditions are met this is what Iv got however the quer

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  •  不思量自难忘°
    2021-01-01 05:38

    Close, but no cigar. :)

    SELECT * FROM table 
    WHERE (x BETWEEN 20 AND 80) AND 
    (y BETWEEN 20 AND 120) AND 
    (z BETWEEN 10 AND 40) LIMIT 0 , 30
    

    To explain, SQL servers generally evaluate x BETWEEN val1 AND val2 the same as x >= val1 AND x <= val2. The way your original query was written, the first condition would be x >= 120 AND x <= 20), which obviously wasn't what you intended.

    The parentheses around the different conditions make sure that each is evaluated completely before the AND is considered. It makes a difference most of the time in SQL, and even when it doesn't it's a good idea to use them so your intentions are clear 6 months from now when you (or someone else) has to look at the query again.

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