JDBC开发步骤

Posted 2020-11-24 墨染千城

 1.抛给 java 虚拟机

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class Demo01 {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //1.注册驱动
        Class.forName("com.mysql.jdbc.Driver");
        //2.连接数据库(获取连接对象)
        String url="jdbc:mysql://127.0.0.1:3306/java 1018?characterEncoding=UTF-8";
        String user="root";
        String password="123456";
        Connection con = DriverManager.getConnection(url,user,password);
        //System.out.println(con);
        //3.获得语句执行对象
        Statement sta = con.createStatement();
        String sql = "insert into sort(sname) values(‘小裙子‘)";
        //4.执行sql语句
        int row= sta.executeUpdate(sql);
        System.out.println(row);
        //5.释放资源（先开的后关）
        sta.close();
    }
}

 2.try……catch……

package com.oracle.demo01;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;



public class Demo05 {
    public static void main(String[] args) {
        PreparedStatement pst=null;
        Connection con=null;
        //1.注册驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
            //2.获取连接对象
            String url="jdbc:mysql://127.0.0.1:3306/java 1018?characterEncoding=UTF-8";
            String user="root";
            String password="123456";
            con = DriverManager.getConnection(url,user,password);
            //3.获取语句执行对象
            String sql="update sort set sname=? where sid=?";
            pst=con.prepareStatement(sql);
            pst.setInt(2, 5);
            pst.setString(1, "小裙子");
            //4.执行sql语句
            int row =pst.executeUpdate();
            System.out.println(row);
        } catch (ClassNotFoundException | SQLException e) {
            
            e.printStackTrace();
        }finally {
            //5.释放资源
            try {
                pst.close();
                con.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
    }
}

3.封装为静态类

package com.oracle.demo01;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class JDBCUtils {
    //获取connection对象的方法
    public static Connection getconn() {
        //1.注册驱动
        Connection conn=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            //2.连接数据库(获取连接对象)
            String url="jdbc:mysql://127.0.0.1:3306/java 1018?characterEncoding=UTF-8";
            String user="root";
            String password="123456";
            conn = DriverManager.getConnection(url,user,password);
        } catch (ClassNotFoundException | SQLException e) {
            
            e.printStackTrace();
        }
        return conn;
        
    }
}

4.静态类调用

package com.oracle.demo01;

import java.sql.PreparedStatement;
import java.sql.SQLException;

public class Demo06 {
    public static void main(String[] args) {
        String sql="insert into sort values(?,?)";
        
        PreparedStatement pst=null;
        try {
            pst=JDBCUtils.getconn().prepareStatement(sql);
            pst.setInt(1, 4);
            pst.setString(2, "小裙子");
            
            int row =pst.executeUpdate();
            System.out.println(row);
        } catch (SQLException e) {
            
            e.printStackTrace();
        }finally {
            try {
                pst.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
    }
　　

    //增、删、改 释放资源
    public static void close(Statement pst,Connection conn) {
        if (pst!=null) {
            try {
                pst.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
        if (conn!=null) {
            try {
                conn.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
    }
    //查询 释放资源
    public static void close(ResultSet rs,Statement pst,Connection conn) {
        if (rs!=null) {
            try {
                rs.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
        if (pst!=null) {
            try {
                pst.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
        if (conn!=null) {
            try {
                conn.close();
            } catch (SQLException e) {
                
                e.printStackTrace();
            }
        }
    }

}

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