jdbc

JDBC

1、JDBC简述

Java DataBase Connectivity Java数据库连接，Java语言操作数据库

2、JDBC 编程步骤

• 步骤：

  1. 导入驱动jar包 mysql-connector-java-5.1.37-bin.jar 1.复制mysql-connector-java-5.1.37-bin.jar到项目的libs目录下 2.右键-->Add As Library

  2. 注册驱动

     Class.forName(driverClass)
     //加载MySql驱动
     Class.forName("com.mysql.cj.jdbc.Driver")
     //加载Oracle驱动
     Class.forName("oracle.jdbc.driver.OracleDriver")

  3. 获取数据库连接对象 Connection

     DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/imooc", "root", "root");

  4. 定义sql

     String sql1 = "insert into customer values(null,'小明','123456789','13102587894',3,9999)";
     String sql2 = "delete from customer where id = 10";
     String sql3 = "update customer set name='小明' where id =9";
     String sql4 = "select * from customer";

  5. 获取执行sql语句的对象 Statement

     conn.createStatement();

  6. 执行sql，接受返回结果

     int count1 = st.executeUpdate(sql1);
     int count2 = st.executeUpdate(sql2);
     int count3 = st.executeUpdate(sql3);//或者exexute返回boolean
     ResultSet set =  stat.executeQuery(sql4);

  7. 处理结果

     while (set.next()){//如果有数据，rs.next()返回true
            int id = set.getInt("id");//字段名或者列号
            String name = set.getString(2);
            System.out.println(id+","+name+","+salary);
     }

      

  8. 释放资源

     set.close()；
     stat.close();
     conn.close()；

  9.