mysql - 如何在 SQL 中正确使用临时表

Question

我试图使用临时表来简化我的查询，但我收到一条错误消息。这是我的查询：

SELECT E.ID, E.name
INTO #TmpEmplyee
FROM Employee E, Outsourcing O, Student S
WHERE E.ID NOT IN (SELECT ID FROM Student UNION SELECT ID FROM Outsourcing)

SELECT R.name, I.startDate, T.name
FROM Role R, Inn I, #TmpEmplyee T
WHERE I.name = R.name AND I.ID = T.id

错误是：

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM Employee E, Outsourcing O, Student S WHERE E.ID NOT IN (SELECT ID FROM Stud' at line 3

谢谢您的帮助！

Answer 1

在 mysql 中，您需要在查询之前创建临时表。您也不需要 FROM 中的 Outsourcing O, Student S，因为您没有从中选择：

INSERT INTO #TmpEmplyee
SELECT E.ID, E.name
FROM Employee E
WHERE E.ID NOT IN (SELECT ID FROM Student UNION SELECT ID FROM Outsourcing)

Answer 2

试试这个，

SELECT R.name, I.startDate, T.name
FROM    Role R 
        INNER JOIN Inn I
            ON I.name = R.name
        INNER JOIN
        (
            SELECT E.ID, E.name
            -- remember that the join below produces CROSS JOIN
            FROM Employee E, Outsourcing O, Student S
            WHERE E.ID NOT IN ( SELECT ID FROM Student 
                                UNION 
                                SELECT ID FROM Outsourcing)
        ) T ON I.ID = T.id

Answer 3

要从选择创建临时表，您应该使用此语法

CREATE TEMPORARY TABLE mytemptable 
SELECT Field1, Field2 
FROM mytable;