尝试创建表时出错

Question

我找不到语法错误：

Drop Table if Exists Classes;
Drop Table if Exists Grades;
Drop Table if Exists Faculty;
Drop Table if Exists Students;

CREATE TABLE Faculty (StaffID INTEGER( 11 ),
StaffFirstName VARCHAR( 50 ),
StaffLastName VARCHAR( 50 ),
StaffPhone VARCHAR, CONSTRAINT PRIMARY KEY (StaffID) ) ENGINE = innodb;

CREATE TABLE Students (
  StudentID INTEGER( 11 ) NOT NULL ,
   StudentFirstName VARCHAR( 50 ) NOT NULL ,
   StudentLastName VARCHAR( 50 ) NOT NULL ,
   StudentPhone VARCHAR NOT NULL,
   CONSTRAINT PRIMARY KEY (StudentID)
  ) ENGINE = innodb ;

 CREATE TABLE Classes (
  ClassID VARCHAR NOT NULL ,
  ClassName VARCHAR( 50 ) NOT NULL ,
  CONSTRAINT PRIMARY KEY (ClassID)
) ENGINE = innodb ;

 CREATE TABLE Grades (
 StaffID INTEGER( 11 ) NOT NULL ,  
 StudentID INTEGER( 11 ) NOT NULL ,
 ClassID VARCHAR (11)NOT NULL ,
   Grade VARCHAR( 2 ),  
   CONSTRAINT PRIMARY KEY (StaffID, StudentID, ClassID),
 FOREIGN KEY (StaffID) references Faculty(StaffID),
 FOREIGN KEY (StudentID) references Students(StudentID),
 FOREIGN KEY (ClassID) references Classes(ClassID)
 ) ENGINE = innodb ;'

我试过去掉空格和逗号并添加一些我找不到的地方。这是错误：

CREATE TABLE Faculty (StaffID INTEGER( 11 ),
StaffFirstName VARCHAR( 50 ),
StaffLastName VARCHAR( 50 ),
StaffPhone VARCHAR, CONSTRAINT PRIMARY KEY (StaffID) ) ENGINE = innodb;

MySQL 说：

文档 #1064 - 您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以在第 4 行的 ' CONSTRAINT PRIMARY KEY (StaffID) ) ENGINE = innodb' 附近使用正确的语法

Answer 1

我对 MySql 不是很熟悉，但是是否有必要为 Integer 列添加长度？你是说第一列的类型是

整数 (11)