Question

我有一个复杂的查询，可以跨多个列执行多个匹配，然后按相关性进行排序。

在我添加WHERE 'rank' > 0

之前，一切正常

然后返回一个空的结果集。

如果我删除了＆＃39; WHERE＆＃39;声明然后我可以看到顶部最高匹配的所有结果。

有人可以帮我解决问题吗？＆＃39; :-D我错了!!

SELECT *, CASE WHEN companyName = 'gfdgfs' THEN 2 ELSE 0 END 
+ CASE WHEN companyName LIKE '%gfdgfs%' THEN 1 ELSE 0 END 
+ CASE WHEN companyName = 'potato' THEN 2 ELSE 0 END 
+ CASE WHEN companyName LIKE '%potato%' THEN 1 ELSE 0 END 
+ CASE WHEN address1 = 'gfdgfs' THEN 2 ELSE 0 END 
+ CASE WHEN address1 LIKE '%gfdgfs%' THEN 1 ELSE 0 END 
+ CASE WHEN address1 = 'potato' THEN 2 ELSE 0 END 
+ CASE WHEN address1 LIKE '%potato%' THEN 1 ELSE 0 END 
AS rank 
FROM clients 
WHERE rank > 0
ORDER BY rank

修改

我删除了rank字周围的单引号，现在在where子句＆＃39;

中获得了未知的列级别

Answer 1

从rank删除单引号并尝试。无论如何，我不认为MySQL会支持包含别名的WHERE子句 - 请检查this。

使用HAVING而不是WHERE：

SELECT *, CASE WHEN companyName = 'gfdgfs' THEN 2 ELSE 0 END + CASE WHEN companyName LIKE '%gfdgfs%' THEN 1 ELSE 0 END + CASE WHEN companyName = 'potato' THEN 2 ELSE 0 END + CASE WHEN companyName LIKE '%potato%' THEN 1 ELSE 0 END + CASE WHEN address1 = 'gfdgfs' THEN 2 ELSE 0 END + CASE WHEN address1 LIKE '%gfdgfs%' THEN 1 ELSE 0 END + CASE WHEN address1 = 'potato' THEN 2 ELSE 0 END + CASE WHEN address1 LIKE '%potato%' THEN 1 ELSE 0 END AS rank FROM clients HAVING rank > 0 ORDER BY rank

Answer 2

试试这个：

SELECT * 
FROM (SELECT *, CASE WHEN companyName = 'gfdgfs' THEN 2 ELSE 0 END 
              + CASE WHEN companyName LIKE '%gfdgfs%' THEN 1 ELSE 0 END 
              + CASE WHEN companyName = 'potato' THEN 2 ELSE 0 END 
              + CASE WHEN companyName LIKE '%potato%' THEN 1 ELSE 0 END 
              + CASE WHEN address1 = 'gfdgfs' THEN 2 ELSE 0 END 
              + CASE WHEN address1 LIKE '%gfdgfs%' THEN 1 ELSE 0 END 
              + CASE WHEN address1 = 'potato' THEN 2 ELSE 0 END 
              + CASE WHEN address1 LIKE '%potato%' THEN 1 ELSE 0 END 
              AS rank 
        FROM clients 
      ) AS A 
WHERE rank > 0
ORDER BY rank;

MySQL CASE WHEN where子句导致失败

2 个答案: