PreparedStatement的增删改

案例9：preparedStatement增删改：

package com.java.JDBC;


import java.sql.*;


public class JDBCTest09 {
    public static void main(String[] args) {
        
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        
        try {
            // 1 注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            // 2 获取连接
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase","root","333");
            // 3 获取预编译数据库操作对象
            
            // 插入数据
            /*String sql = "insert into dept(deptno,dname,loc) values(?,?,?)";
            ps = conn.prepareStatement(sql);
    
            ps.setString(1,"60");
            ps.setString(2,"销售部");
            ps.setString(3,"上海");*/
            
            // 更新数据
            /*String sql = "update dept set dname = ?, loc = ? where deptno = ?";
            ps = conn.prepareStatement(sql);
    
            ps.setString(1,"研发一部");
            ps.setString(2,"重庆");
            ps.setString(3,"60");*/
            
            // 删除数据
            String sql = "delete from dept where deptno = ?";
            ps = conn.prepareStatement(sql);
            
            ps.setString(1,"60");
            
            // 4 执行sql语句
            int count = ps.executeUpdate();
            // System.out.println(count == 1 ? "插入成功" : "插入失败");
            System.out.println(count == 1 ? "删除成功" : "删除失败");
            
            // 5 处理返回结果集
            
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 6 释放资源
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
    
            if (ps != null) {
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
    
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}