Question

我收到此错误消息...

Msg 156，Level 15，State 1，Line 20
关键字'CONSTRAINT'附近的语法不正确。

我完成了我的研究，但我仍然坚持完成这个脚本。

这就是我输入的内容。

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如何知道每个约束实际属于哪个表？

Answer 2

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
CONSTRAINT pk_student PRIMARY KEY (stuid, stulname, stufname, stugender, stubirthdate),);

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

CREATE TABLE SEMESTER (
year int not null ,
semid int not null
CONSTRAINT pk_semester PRIMARY KEY (semid, year));;

根据我的理解这里必须在学生的表格内创建约束和第二个表你在课堂上创建2次主键（标题）和来到第三表semid本身不在学期表中

关键字'CONSTRAINT'附近的语法不正确

2 个答案: