小编use*_*147的帖子

我是SQL的新手,我正在尝试定义一个2个表Hospital,Hospital_Address但是当我尝试在其中添加外键时Hospital_Address会抛出一个错误:"1215: Cannot add foreign key"

create table Hospital (
             HId Int not null,  
           HName varchar(40) not null, 
           HDept int, Hbed Int, 
         HAreaCd int not null, 
         Primary Key (HId)
                      );

create table Hospital_Address (
                HAreaCd Int not null,
                  HArea varchar(40) not null,
                  HCity varchar(40), 
                  HAdd1 varchar(40),
                  HAdd2 varchar(40), 
                  Primary Key (HArea), 
                 foreign key (HAreaCd) references Hospital (HAreaCd));

请帮助我这方面.提前致谢.