mysql - 复杂的 Mysql 字符串不返回行

Question

我在“服务”表上有 3 行:

ID | name | ObrID
 0 |   A  |  1
 1 |   B  |  2
 2 |   C  |  -1

-1是不存在的Obr，服务2不包含任何Obr或已被删除。

如果我使用 select * from Services 获取，它会按预期工作，但如果我执行搜索 sql:

select 
    *,
    (select Name from Obrs where ID=ObrID) as ObrName
from
    Services
where
    (select Name from Obrs where ID=ObrID) like '%SEARCH_STRING%'

它不返回最后一行。有什么办法让它返回类似的内容:

ID | name | ObrID | ObrName
 0 |   A  |   1   |   ObrA
 1 |   B  |   2   |   ObrB
 3 |   C  |   -1  |   NULL

Answer 1

您想要使用左连接。

http://www.tizag.com/mysqlTutorial/mysqlleftjoin.php

SELECT s.*,o.ObrName from Services s
    LEFT JOIN Obrs o ON ID=ObrID
    WHERE OrbName LIKE '%$SEARCH_STRING%' OR OrbName IS NULL

或者:

SELECT * FROM (select s.*,o.ObrName from Services s
    LEFT JOIN Obrs o ON ID=ObrID) tmp
    WHERE OrbName LIKE '%$SEARCH_STRING%' OR OrbName IS NULL