mysql - 关键字 'CONSTRAINT' 附近的语法不正确

Question

我收到此错误消息...

Msg 156, Level 15, State 1, Line 20
Incorrect syntax near the keyword 'CONSTRAINT'.

我已经完成了研究，但我仍然坚持要完成这个脚本。

这是我输入的内容。

DROP TABLE SEMESTER; 
DROP TABLE CLASS;
DROP TABLE STUDENT;

CREATE TABLE STUDENT (
stuid int not null,
stulname CHAR(40) not null,
stufname CHAR(40) not null,
stugender CHAR(1) not null,
stubirthdate DATE not null);

CREATE TABLE CLASS (
title CHAR(40) not null PRIMARY KEY,
instructor CHAR(40) not null );

CREATE TABLE SEMESTER (
year int not null ); 


CONSTRAINT pk_student PRIMARY KEY (stuid, stulname, stufname, stugender, stubirthdate),
CONSTRAINT pk_class PRIMARY KEY (title, instructor),
CONSTRAINT pk_semester PRIMARY KEY (semid, year)); 

Answer 1

我认为那些CONSTRAINT 语句需要在 CREATE TABLE 语句中。例如，STUDENT 表应该如下所示:

CREATE TABLE STUDENT (
    stuid int not null,
    stulname CHAR(40) not null,
    stufname CHAR(40) not null,
    stugender CHAR(1) not null,
    stubirthdate DATE not null,
    CONSTRAINT pk_student PRIMARY KEY (stuid, stulname, stufname, stugender, stubirthdate), 
);

否则，RDBMS 怎么知道每个约束实际上属于哪个表？