jdbc 2.0

1.Statement接口不能接受参数

2.PreparedStatement接口在运行时接受输入参数

3.CallableStatement接口也可以接受运行时输入参数，当想要访问数据库存储过程时使用

4.示例一：

package com.rong.web;

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

public class Test2 {

    /**
     * @author 容杰龙
     */
    public static void main(String[] args) {
        Connection conn = getConnection();
        PreparedStatement ps = null;
        String sql = "insert into student(name,age) values(?,?)";
        if (conn != null) {
            try {
                // 预处理语句对象 可用占位符？解决sql注入漏洞，占位符位置从1开始
                ps = conn.prepareStatement(sql);
                ps.setString(1, "rjl");
                ps.setInt(2, 18);
                // 是否返回结果集，此时是false
                boolean flag = ps.execute();
                System.out.println(flag);
                // 返回执行结果的影响行数，此时返回值为1
                int effects = ps.executeUpdate();
                System.out.println(effects);
                /////////批处理/////////
                String sql1 = "insert into student(name,age) values('one',28)";
                String sql2 = "insert into student(name,age) values('two',27)";
                // PreparedStatement构造方法必须有字符串参数
                ps = conn.prepareStatement("");
                ps.addBatch(sql1);
                ps.addBatch(sql2);
                int[] ints = ps.executeBatch();
                for (int i : ints) {
                    System.out.println(i);
                }
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                // 关闭资源
                try {
                    if (ps != null) {
                        ps.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                try {
                    if (conn != null) {
                        conn.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        }

    }
    public static Connection getConnection() {
        Connection connection=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://127.0.0.1:3306/rjl";
            String user="root";
            String password="123123";
            connection = DriverManager.getConnection(url, user, password);
            
        } catch (Exception e) {
            e.printStackTrace();
        }
        return connection;
    }

}

 5.示例二：

MySQL存储过程

DELIMITER $$
CREATE PROCEDURE getPrice(INOUT myName VARCHAR(20),OUT age INT(20))
BEGIN
SET myName="rjl";
SET age=22;
END $$

java操作

package com.rong.web;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.SQLException;

public class Test3 {
    public static void main(String[] args) {
        Connection connection = Test2.getConnection();
        if (connection != null) {
            String sql = "call getPrice(?,?)";
            try {
                //创建存储过程的语句操作对象
                CallableStatement cs = connection.prepareCall(sql);
                //IN类型参数直接设置set即可
                //第一个参数为INOUT类型，需要设置set参数，并注册参数
                cs.setString(1, "kobe");
                cs.registerOutParameter(1, java.sql.Types.VARCHAR);
                //第二个参数为OUT类型，也需要注册
                cs.registerOutParameter(2, java.sql.Types.INTEGER);
                boolean flag = cs.execute();
                System.out.println(flag);
                //获取执行存储过程后的OUT结果
                String name = cs.getString(1);
                int age = cs.getInt(2);
                System.out.println(name + ":" + age);
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}