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表格1

表 2

表3

现在我如何从 tm_id=10 的 table2 中选择 project_title

完成这项任务的最佳方法是什么?

4

5 回答 5

2
SELECT t2.project_title FROM table2 AS t2
JOIN table3 AS t3 ON t3.project_id = t2.project_id
WHERE t3.tm_id = 10;
于 2013-05-29T06:02:09.623 回答
1

我认为一个简单的INNER JOIN就足够了你的需要。

SELECT  a.*, c.project_title
FROM    Online_team a
        INNER JOIN team_project b
            ON a.tm_id = b.tm_id
        INNER JOIN online_team_projects c   
            ON b.project_ID = c.project_ID
WHERE   a.tm_id = 10

要进一步了解有关联接的更多信息,请访问以下链接:

但是,如果您不需要来自 的任何列Online_team,则可以将其从联接列表中删除。

SELECT  c.project_title
FROM    team_project b
        INNER JOIN online_team_projects c   
            ON b.project_ID = c.project_ID
WHERE   b.tm_id = 10
于 2013-05-29T06:02:14.763 回答
1

使用如下查询

 SELECT table2.project_title  from table2,table3 where table2.project_id = table3.project_id and table3.tm_id = 10
于 2013-05-29T06:03:29.843 回答
0
SELECT
  otp.project_title
FROM online_team_projects otp,
  team_project tp
WHERE otp.project_id = tp.project_id
    AND tp.tm_id = 10
于 2013-05-29T06:02:23.013 回答
0

您可以使用这种方法:

SELECT otp.project_title
FROM online_team ot
INNER JOIN online_team_projects otp USING (project_id)
WHERE ot.tm_id = 10
于 2013-05-29T06:04:44.203 回答