JDBC

JDBC说白了就是一堆接口

import java.sql.*;

public class TestJDBC {

      public static final String USER = "root";
      public static final String PASSWD = "1995";
      public static final String URI = "jdbc:mysql://localhost:3306/java";
      public static final String DRIVER="com.mysql.jdbc.Driver";
    public static void main(String[] args) {
        ResultSet rs = null;
        Statement stmt = null;
        Connection conn = null;


        try {
            Class.forName(DRIVER);
            conn = DriverManager.getConnection(URI, USER, PASSWD);
            stmt = conn.createStatement();
            rs = stmt.executeQuery("select * from test");
            while(rs.next()) {//遍历每一行
                System.out.println(rs.getInt("id"));//输出id字段
                System.out.println(rs.getString("name"));//输出name字段
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {//这段代码非常严谨
            try {
                if(rs != null) {
                    rs.close();
                    rs = null;
                }
                if(stmt != null) {
                    stmt.close();
                    stmt = null;
                }
                if(conn != null) {
                    conn.close();
                    conn = null;
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

}