create table Type(tpid int PRIMARY KEY GENERATED ALWAYS AS IDENTITY (START WITH 1,INCREMENT BY 1),tpname varchar(20) ,UNIQUE(tpname))create table Servers(id int PRIMARY KEY GENERATED ALWAYS AS IDENTITY (START WITH 1,INCREMENT BY 1),address varchar(20),ip varchar(16),name varchar(20),password varchar(20),type int, dbs long varchar, UNIQUE(ip),FOREIGN KEY(type) references Type(tpid))
创建表的sql如上,想删除这2个表里的数据,总是提示有外键约束。
用的是Derby数据库,但是sql和oracle数据库应该相同。
下面这个表也有外键,删的时候就不报错create table UsersServers(uuid int ,ssid int,FOREIGN KEY(uuid) references Users(id),FOREIGN KEY (ssid) references Servers(id))