Question

我正在尝试在名字和姓氏字段上搜索查询

这是我的查询

SELECT d.title, GROUP_CONCAT(u.firstName,' ',u.lastName) as fullname
FROM DEALS d 
left JOIN USER u ON u.idUser = d.userId 
WHERE ((d.title LIKE  '%goutham%' OR d.keywords LIKE  '%goutham%')
OR fullname LIKE  '%goutham%') AND d.isPublic=1

但我得到了

'where子句'中的未知列'fullname'

Answer 1

您无法在where中使用列别名。它与您的查询的其余部分无关。

您没有GROUP BY，因此我怀疑GROUP_CONCAT()无意。相反，你想要CONCAT()。您可以在WHERE中重复表达式，但我认为您应该查看每个组件：

SELECT d.title, CONCAT(u.firstName, ' ', u.lastName) as fullname
FROM DEALS d left JOIN USER
     u
     ON u.idUser = d.userId 
WHERE (d.title LIKE '%goutham%' OR
       d.keywords LIKE '%goutham%' OR
       u.firstName LIKE '%goutham%' OR
       u.lastName LIKE '%goutham%'
      ) AND
      d.isPublic = 1;

如果您关心性能并且正在寻找单词，那么您可能需要研究MySQL的全文索引功能。

如果您仍想查看组合，我建议您重复使用表达式：

WHERE (d.title LIKE '%goutham%' OR
       d.keywords LIKE '%goutham%' OR
       CONCAT(u.firstName, ' ', u.lastName) LIKE '%goutham%'
      ) AND
      d.isPublic = 1;

Answer 2

问题的直接原因是您无法引用同一查询的SELECT子句中WHERE子句中定义的别名。解决方案是重复整个表达式而不是使用别名。但是，根据您的评论，您确实要检查名字，所以请执行以下操作：

SELECT
    d.title,
    CONCAT(u.firstName, ' ', u.lastName) AS fullname
FROM DEALS d 
LEFT JOIN USER u
    ON u.idUser = d.userId 
WHERE
    (d.title LIKE '%goutham%' OR
    d.keywords LIKE '%goutham%' OR
    u.firstName LIKE  '%goutham%') AND d.isPublic = 1;

mysql组concat unknow列错误

2 个答案: