Question

我有两个表，我想使用两个表中的数据创建一个具有相同属性的新表。以下是我正在尝试的代码

/* Create a table called NAMES */
CREATE TABLE NAMES(Id integer PRIMARY KEY, Name varchar(100));
CREATE TABLE GAMES(Id integer PRIMARY KEY, Name varchar(100));
CREATE TABLE JJ(Id integer PRIMARY KEY, Name varchar(100));

/* Create few records in this table */
INSERT INTO NAMES VALUES(1,'Tom');
INSERT INTO NAMES VALUES(2,'Lucy');
INSERT INTO NAMES VALUES(3,'Frank');
INSERT INTO NAMES VALUES(4,'Jane');
INSERT INTO NAMES VALUES(5,'Robert');
INSERT INTO GAMES VALUES(7,'Football');
INSERT INTO GAMES VALUES(6,'Rugby');
COMMIT;

/* Display all the records from the table */
SELECT * FROM NAMES;
SELECT * FROM GAMES;
INSERT INTO JJ (Id, Name) VALUES((SELECT * FROM NAMES), (SELECT * FROM GAMES));

SELECT * FROM JJ; 'Error: near line 21: sub-select returns 2 columns - expected 1'

Answer 1

这将适用于oracle

INSERT INTO JJ (Id, Name)((SELECT * FROM NAMES) union all(SELECT * FROM GAMES));

对于mysql：

   insert into JJ select * from Names union all select * from Games;

但是正如Zaynul所说，当两个主键匹配时，它将引发错误！

Answer 2

您尝试合并两个表的方式并不更好，因为两个不同的表主键可能相同，这将在插入第三个表（重复键）时引发错误。我希望更改您的表结构，使所有三个表的主键自动递增并仅推送名称而不是ID

INSERT INTO JJ ( Name)
select name from (
SELECT name FROM NAMES
union all
SELECT name FROM GAMES
) t

Answer 3

我建议将JJ声明为：

CREATE TABLE JJ (
    Id integer auto_increment PRIMARY KEY,
    Name varchar(100)
);

insert into jj (name)
    select name from names union all
    select game from games;

如何联接两个具有相同属性的表？

3 个答案: