mysql Getting the same auto_increment value into another

问题

This may have a really easy answer. I have done much database stuff for a while. I am trying to get the auto_increment value from one table inserted into the value on another table. is there an easy way of doing this. For eg i have done:

CREATE TABLE table_a (
id int NOT NULL AUTO_INCREMENT,
a_value  varchar(4),
PRIMARY KEY (id)
);

CREATE TABLE table_b (
id int NOT NULL,
b_value varchar(15),
FOREIGN KEY (id) REFERENCES table_a (id)
);

Now i want to insert values into the table but I would like 'id' values for table_a and table_b to be the same. So far i have:

INSERT INTO table_a VALUES (NULL, 'foobar');

But I do not know how to go about extracting the auto_incermented 'id' number from table_a into the the 'id' value of table_b. I have looked at SELECT @id = LAST_INSERT_ID() but can not get it to work.

回答1:

You cannot do that at once. You'll have to first insert into the first table:

INSERT INTO table_a (a_value) VALUES ('foobar');

and then insert into the second using the generated id:

INSERT INTO table_b (id, b_value) VALUES (@@IDENTITY, 'foobar');

回答2:

LAST_INSERT_ID() and no need for the select statement part.

来源：https://stackoverflow.com/questions/4297462/mysql-getting-the-same-auto-increment-value-into-another