JDBC - 第一天

承苏凯

发布于 2020-07-24 09:59:29

3680

发布于 2020-07-24 09:59:29

文章被收录于专栏：唯手熟尔唯手熟尔

JDBC第一天

JDBC的组成框图

JDBC API

供开发者调用的接口 -> java.sql和javax.sql

Driver类
Connection接口
Statement接口
ResultSet接口

JDBC Driver Manager

管理不同的JDBC驱动

JDBC的使用

加载数据库驱动

//加载驱动
try {
  //获取Driver的运行时类
   Class.forName ("com.mysql.cj.jdbc.Driver");
   //获取连接
   String url = "jdbc:mysql://localhost:3306/library?useUnicode=true&characterEncoding=UTF-8";
   String user = "root";
   String password = "Csk513434";
}
catch (ClassNotFoundException e) {
   e.printStackTrace ();
}

获取Connection，Java程序与数据库的一次连接

Connection connection = DriverManager.getConnection (url, user, password);

创建Statement对象，执行sql语句

//增加删除修改 使用statement.executeUpdate (sql)
	String sql = "insert into book(name,author,publish) values ('承苏凯的故事','承苏凯','苏州出版社')";
	String sql = "insert into book(name,author,publish) values ('张三的故事','张三','北京出版社')";
	String sql = "update book set name = '李四的书'";
	String sql = "delete from student";
	Statement statement = connection.createStatement ();
	int result = statement.executeUpdate (sql);
	System.out.println (result);

创建ResultSet对象，如果需要接受返回值，保存Statement执行之后所查询的结果

//删除操作使用 使用statement.executeQuery (sql)
String sql = "select * from book";
Statement statement = connection.createStatement ();
ResultSet resultSet = statement.executeQuery (sql);
while (resultSet.next ()) {
   Integer id = resultSet.getInt ("id");
   String name = resultSet.getString (2);
   String author = resultSet.getString (3);
   String address = resultSet.getString (4);
   System.out.println (id + "-" + name + "-" + author + "-" + address);
}