Question

coachID和teamCoach包含相同的数据，但具有不同的列名。因此我无法加入他们。我该怎么办？

SELECT tblCoaches.coachID AS "Coach ID", 
       tblCoaches.coachName AS "Coach Name", 
       tblCoaches.coachCity AS "Coach City", 
       tblTeams.teamName AS "Team Name"
FROM tblCoaches
INNER JOIN tblTeams ON **tblCoaches.coachID = tblTeams.teamCoach**
      AND (coachID IN (SELECT teamCoach FROM tblTeams))
WHERE teamIsRec IS NULL;

Answer 1

此结构应该有效

    SELECT
      tblCoaches.coachID AS "Coach ID",
      tblCoaches.coachName AS "Coach Name",
      tblCoaches.coachCity AS "Coach City",
      tblTeams.teamName AS "Team Name"
    FROM tblCoaches
    INNER JOIN tblTeams
      ON tblCoaches.coachID = tblTeams.teamCoach   -- IDs that linked the tables
    WHERE teamIsRec IS NULL;

Answer 2

如果您想在特定列上进行连接：

select * from table2 JOIN table1 ON table2.id = table1.id_a

在你的情况下，我认为该行

AND (coachID IN (SELECT teamCoach FROM tblTeams))

不执行任何逻辑，因为INNER JOIN仅接受两个表中的列值。所以你的语法应该是这样的：

SELECT tblCoaches.coachID AS "Coach ID", tblCoaches.coachName AS "Coach Name", tblCoaches.coachCity AS "Coach City", tblTeams.teamName AS "Team Name"
FROM tblCoaches
INNER JOIN tblTeams ON tblCoaches.coachID = tblTeams.teamCoach
WHERE teamIsRec IS NULL;

使用相同数据但不同列名连接表

2 个答案: