实例分析
首先创建2张如下表:
CREATE TABLE a
(aID int(4) AUTO_INCREMENT PRIMARY KEY ,
aNum char( 20 )
);
CREATE TABLE b(
bID int(4) NOT NULL AUTO_INCREMENT PRIMARY KEY ,
bName char( 20 )
) ;CREATE TABLE a
(a首先创建2张如下表:
CREATE TABLE a
(aID int(4) AUTO_INCREMENT PRIMARY KEY ,
aNum char( 20 )
);
CREATE TABLE b(
bID int(4) NOT NULL AUTO_INCREMENT PRIMARY KEY ,
bName char( 20 )
) ;CREATE TABLE a
(a