JDBC
JDBC
下载一个数据库驱动jar包,mysql-connector-java ---> 项目新建一个lib目录 ---> 驱动jar包导入到lib目录 ---> 右键jar包选Add as library
连MySQL数据库的demo:
public class JDBCDemo{
public static void main(String[] args) throws ClassNotFoundException,SQLException{
//1.加载驱动
Class.forName("com.mysql.jdbc.Driver"); //固定写法,加载驱动
//2.用户信息和url
String url = "jdbc:mysql://localhost:3306/jdbcstudy? useUnicode=true&characterEncoding=utf8&useSSL=true";
String username = "root";
String password = "123456";
//3.连接成功,数据库对象 Connection 代表数据库
Connection connection = DriverManager.getConnection(url,username,password);
//4.执行SQL对象Statement执行SQL的对象
Statement statement = connection.createStatement();
//5.执行SQL的对象去执行SQL,可能存在结果,查看返回结果
String sql = "SELECT * FROM users";
ResultSet resultSet = statement.executeQuery(sql);
while(resultSet.next()){
System.out.println("id="resultSet.getObject("id"));
System.out.println("name="resultSet.getObject("NAME"));
System.out.println("pwd="resultSet.getObject("PASSWORD"));
System.out.println("email="resultSet.getObject("email"));
System.out.println("birth="resultSet.getObject("birthday"));
System.out.println("================================");
}
//6.释放连接
resultSet.close();
statement.close();
connection.close();
}
}
步骤总结:
- 加载驱动
- 连接数据库DriverManager
- 获得执行SQL的对象Statement
- 获得返回的结果集
- 释放连接