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();
             }
         }
     }
 }