MySQL查詢與WHERE IF和FIND_IN_SET（）函數

Question

我一直在使用下面的查詢：後4個成功匹配

"SELECT * FROM mytable WHERE IF(FIND_IN_SET(column1,'$searchString') > 0,1,0) 
+ IF(FIND_IN_SET(column2, '$searchString') > 0, 1, 0) 
+ IF(FIND_IN_SET(column3, '$searchString') > 0, 1, 0)+ 
IF(FIND_IN_SET(column4, '$searchString') > 0, 1, 0) > 0"; 

所以（萬一），做的查詢就會變成以下??：

"SELECT * FROM mytable WHERE 1+1+1+1 > 0"; 

請確保我的假設是否正確。提前致謝。

Answer 1

是的，但你可以讓這個短

SELECT * FROM mytable 
WHERE 
(
    FIND_IN_SET(column1, '$searchString') > 0 + 
    FIND_IN_SET(column2, '$searchString') > 0 + 
    FIND_IN_SET(column3, '$searchString') > 0 + 
    FIND_IN_SET(column4, '$searchString') > 0 
) > 0 

Answer 2

通常情況下，你會做這種類型的比較與or除非你想真的要算匹配：

SELECT * 
FROM mytable 
WHERE (FIND_IN_SET(column1, '$searchString') > 0 OR 
     FIND_IN_SET(column2, '$searchString') > 0 OR 
     FIND_IN_SET(column3, '$searchString') > 0 OR 
     FIND_IN_SET(column4, '$searchString') > 0 
    );