外键约束被参考的必须是主键
Java连接Oracle数据库
create table stu
(
id number(6),
name varchar2(20) constraint stu_name_nn not null,
sex number(1),
age number(3),
sdate date,
grade number(2) default 1,
class number(4),
email varchar2(50),
constraint stu_class_fk foreign key (class) references class(id),
constraint stu_id_pk primary key(id),
constraint stu_name_email_uni unique(email,name)
);
create table class
(
id number(4) primary key,
name varchar2(20) not null
);
Java连接Oracle数据库
import java.sql.*;
import javax.naming.spi.DirStateFactory.Result;
public class TestJDBC {
public static void main(String[] args) throws Exception{
ResultSet rs =null;
Statement stmt = null;
Connection conn = null;
try{
Class.forName("oracle.jdbc.driver.OracleDriver");//new oracle.jdbc.driver.OracleDriver();
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl","scott","shousi520");
stmt = conn.createStatement();
rs = stmt.executeQuery("select *from dept");
while(rs.next()){
System.out.println(rs.getString("deptno"));
System.out.println(rs.getInt("deptno"));
}
}catch(ClassNotFoundException e){
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
if(rs != null){
rs.close();
rs=null;
}
if(stmt != null){
stmt.close();
stmt=null;
}
if(conn != null){
conn.close();
conn=null;
}
}catch(SQLException e){
e.printStackTrace();
}
}
}
}