Question

我创建了一个SQL语句，该语句应该返回按相关性排序的项目列表，这些项目是提供的三个单词。（TAG_1，TAG_2等）。这是代码：

$sql = mysql_query("SELECT * FROM SEARCH_POSTS WHERE(
    POST_TAG_1 LIKE '%{$_POST['TAG_1']}%'
    OR POST_TAG_1 LIKE '%{$_POST['TAG_2']}%'
    OR POST_TAG_1 LIKE '%{$_POST['TAG_3']}%'
    OR POST_TAG_2 LIKE '%{$_POST['TAG_1']}%'
    OR POST_TAG_2 LIKE '%{$_POST['TAG_2']}%'
    OR POST_TAG_2 LIKE '%{$_POST['TAG_3']}%'
    OR POST_TAG_3 LIKE '%{$_POST['TAG_1']}%'
    OR POST_TAG_3 LIKE '%{$_POST['TAG_2']}%'
    OR POST_TAG_3 LIKE '%{$_POST['TAG_3']}%'
) ORDER BY(
    CASE 
    WHEN  POST_TAG_1 LIKE '%{$_POST['TAG_1']}%' THEN 1
    ELSE 0
    END CASE + 
    CASE 
    WHEN  POST_TAG_1 LIKE '%{$_POST['TAG_2']}%' THEN 1
    ELSE 0 
    END CASE +    
    CASE 
    WHEN  POST_TAG_1 LIKE '%{$_POST['TAG_3']}%' THEN 1
    ELSE 0
    END CASE +
    CASE 
    WHEN  POST_TAG_2 LIKE '%{$_POST['TAG_1']}%' THEN 1
    ELSE 0
    END CASE +     
    CASE 
    WHEN  POST_TAG_2 LIKE '%{$_POST['TAG_2']}%' THEN 1
    ELSE 0 
    END CASE +    
    CASE 
    WHEN  POST_TAG_2 LIKE '%{$_POST['TAG_3']}%' THEN 1
    ELSE 0
    END CASE +
    CASE 
    WHEN  POST_TAG_3 LIKE '%{$_POST['TAG_1']}%' THEN 1
    ELSE 0
    END CASE +     
    CASE 
    WHEN  POST_TAG_3 LIKE '%{$_POST['TAG_2']}%' THEN 1
    ELSE 0 
    END CASE +    
    CASE 
    WHEN  POST_TAG_3 LIKE '%{$_POST['TAG_3']}%' THEN 1
    ELSE 0
    END CASE) DESC");

WHERE子句工作正常，但看起来ORDER BY（...）给了我一个错误。我究竟做错了什么？一切看起来都是有序的。谢谢。

Answer 1

END CASE应为END。 END CASE用于结束存储过程中的CASE语句，它不用于结束CASE表达式。

Answer 2

您正在使用不需要的case。试试这个order by

ORDER  BY( CASE WHEN POST_TAG_1 LIKE '%{$_POST['TAG_1']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_1 LIKE '%{$_POST['TAG_2']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_1 LIKE '%{$_POST['TAG_3']}%' THEN 1 ELSE 0 END +
           CASE WHEN POST_TAG_2 LIKE '%{$_POST['TAG_1']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_2 LIKE '%{$_POST['TAG_2']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_2 LIKE '%{$_POST['TAG_3']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_3 LIKE '%{$_POST['TAG_1']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_3 LIKE '%{$_POST['TAG_2']}%' THEN 1 ELSE 0 END + 
           CASE WHEN POST_TAG_3 LIKE '%{$_POST['TAG_3']}%' THEN 1 ELSE 0 END ) DESC

SQL按顺序排序错误

2 个答案: