JDBC连接数据库

实现步骤

1.加载驱动
	Class.forName("oracle.jdbc.OracleDriver");
2.获取连接对象
	Connection connection = DriverManager
      .getConnection("jdbc:oracle:thin:@localhost:1521/XE", "scott", "tiger");
3.获取sql执行环境
	Statement st = connection.createStatement();
4.执行sql语句
	ResultSet resultSet = st.executeQuery(sql);
5.关闭连接对象
	st.close();
    connection.close();
完整代码如下：
	import java.sql.*;

	public class TestJdbc {
	
	    public static void main(String[] args) throws ClassNotFoundException, SQLException {
	        //1、加载驱动
	        Class.forName("oracle.jdbc.OracleDriver");
	        //2、获取数据库连接对象
	        Connection connection = DriverManager
               .getConnection("jdbc:oracle:thin:@localhost:1521/XE", "scott", "tiger");
	        //3、获取sql执行环境
	        Statement st = connection.createStatement();
	        //4、执行sql语句
	        String sql = "select * from emp";
	        ResultSet resultSet = st.executeQuery(sql);
	        while(resultSet.next()){
	            System.out.print(resultSet.getInt("empno") + "	");
	            System.out.println(resultSet.getString("ename"));
	        }
	        //5、释放资源，关闭连接对象
	        st.close();
	        connection.close();
	    }
	}