JDBC典型程序实例

Posted 2020-06-08

import java.sql.*;

public class AccEmpl{
    
    public static void main(String[] args){
        //对象变量说明
        Connection con;  //数据库连接对象（代表与某一数据库的连接）
        Statement stmt;  //语句对象（可接受和执行一条SQL语句）
        ResultSet rs;    //结果集对象（保存查询返回的结果）
        String sql;
        
        //加载数据库驱动程序
        DriverManager.registerDriver(new com.mysql.jdbc.driver);
        //建立一个与数据库的连接
        con = DriverManager.getConnection("jdbc:mysql:employee");
        //创建一个statement对象
        stmt = con.createStatement();
        
        System.out.println("--------查询所有职工 ，按出生年月排序---------");
        //执行查询
        rs = stmt.executeQuery("SELECT * FROM emp ORDER BY birthday");
        while(rs.next()){
            System.out.print(rs.getString("ename") + "    ");
            System.out.println(rs.getDate("birthday"));
        }
        
        System.out.println("-----统计并显示各部门职工数-----");
        sql = "SELECT departmentNo, COUNT(*) FROM emp Group By departmentNo";
        rs = stmt.executeQuery(sql);
        while(rs.next()){
            System.out.print(rs.getInt(1) + "    ");
            System.out.println(rs.getInt(2));
        }
        
        System.out.println("----------插入一条职工记录------------");
        sql = "INSERT INTO emp VALUES(‘e01‘,‘Lin‘,‘male‘,‘1990-01-22‘,1000)";
        stmt.executeUpdate(sql);
        
        System.out.println("-----------修改职工的工资----------");
        sql = "UPDATE emp SET sal=sal+? WHERE eno = ?";
        PreparedStatement ps = con.prepareStatement(sql);
        ps.setInt(1, 200);
        ps.setString(2, "e10");
        ps.executeUpdate();
        
        con.commit();     //提交修改
        con.close();      //结束一个会话周期
    }
}