JDBC杩炴帴MySQL鎿嶄綔姝ラ

Posted 2022-09-10

鏍囩锛?a href='http://www.mamicode.com/so/1/state' title='state'>state   cal   鍙橀噺   count   static   aik   str   

package testJDBC;

import java.sql.*;

/**

• @Author 灏忕尓涓婂ぉ
• @Email [e-mail]
• @Data 2019/8/28 14:27
• @Version V1.0

• @description JDBC 鏌ヨ鏁版嵁搴撶ず渚?br/>*/
  public class JDBCdemo1

  public static void main(String[] args)
  Connection conn = null;
  Statement statement = null;
  ResultSet resultSet = null;
  //1.娉ㄥ唽鏁版嵁搴撻┍鍔?br/>try

      Class.forName("com.mysql.jdbc.Driver");
      //鍔犺浇涓€涓被鍒板唴瀛樹腑,璇ョ被涓湁涓€闈欐€佷唬鐮佸潡,璇ヤ唬鐮佸潡涓湁娉ㄥ唽椹卞姩鐨勪唬鐮?    //闈欐€佷唬鐮佸潡浼唬鐮佸涓嬶細DriverManager.registerDriver( new Driver() )
  
      //2.鑾峰彇鏁版嵁搴撹繛鎺?    String url = "jdbc:mysql://localhost:3306/" +
              "jt_db" +
              "?characterEncoding=utf-8";
      /**
       * jdbc:mysql:                   鍗忚鍚?     * localhost:3306               涓绘満鍦板潃鍙婄鍙?     * jt_db                        鏁版嵁搴撳悕
       * ?characterEncoding=utf-8     锛?鍙傛暟
       */
  
      String user = "root";           //鏁版嵁搴撹繛鎺ョ敤鎴峰悕
      String passWord = "123456";     //鏁版嵁搴撹繛鎺ュ瘑鐮?
     conn = DriverManager.getConnection(url, user, passWord);
  
      //3.鑾峰彇浼犺緭鍣?
      statement = conn.createStatement();
  
      /**
       * Statement s = con.createStatement();
       * PreparedStatement p = con.preparedStatement();
       *
       *PreparedStatement鏄疭tatement鐨勫瓙绫?     * 鍙互浣跨敤鍗犱綅绗︼紝鏄缂栬瘧鐨勶紝鎵瑰鐞嗘瘮Statement鏁堢巼楂?     *
       * 渚?
       *  String sql = "update user set password=? where username=?";
       *   preparedStatement = conn.prepareStatement(sql);
       *   //preparedStatement.setString(绗琋涓棶鍙?浠ｈ〃鐨勫彉閲?;
       *   preparedStatement.setString(1,password);
       *   preparedStatement.setString(2,username);
       *   preparedStatement.executeUpdate();
       *
       */
  
      //4.鎵цsql璇彞,杩斿洖鎵ц缁撴灉
  
      String sql = "select * from account";
      /**
       * executeQuery(); 鐢ㄤ簬浜х敓鍗曚釜缁撴灉闆嗙殑璇彞,琚敤鏉ユ墽琛?SELECT 璇彞,杩斿洖鍊兼槸涓€涓猂esultSet缁撴灉闆嗗璞?鍏朵腑鍖呮嫭sql鏌ヨ鐨勭粨鏋?     * executeUpdate(); 鐢ㄤ簬鎵ц INSERT銆乁PDATE 鎴?DELETE 璇彞浠ュ強 SQL DDL锛堟暟鎹畾涔夎瑷€锛夎鍙?杩斿洖涓€涓猧nt鍊?璁板綍鍙楀奖鍝嶈褰曡鏁?     */
      resultSet = statement.executeQuery(sql);
  
      //5.澶勭悊缁撴灉
      /**
       * ResultSet 缁撴灉闆嗗璞?     *  ResultSet 鏄墽琛屾煡璇㈢被鐨剆ql璇彞鍚庤繑鍥炵殑缁撴灉闆嗗璞?鍏朵腑鍖呮嫭sql鏌ヨ鐨勭粨鏋?     *  a.閬嶅巻鏁版嵁琛岀殑鏂规硶
       *  next() 鈥?浣挎寚鍚戞暟鎹鐨勭储寮曞悜涓嬬Щ鍔ㄤ竴琛?     *  b.鑾峰彇鏁版嵁鐨勬柟娉?     *  getInt(int columnIndex)
       *  getInt(String columnLable)
       *  getString(int columnIndex)
       *  getString(String columnLable)
       *  getDouble(int columnIndex)
       *  getDouble(String columnLable)
       *  getObject(int columnIndex)
       *  getObject(String columnLable)
       */
      while (resultSet.next()) 
          int id = resultSet.getInt("id");
          String name = resultSet.getString("name");
          double money = resultSet.getDouble("money");
          System.out.println(id + ":" + name + ":" + money);
      
  catch (Exception e)
      e.printStackTrace();
  finally 
  
   //6.閲婃斁璧勬簮
      //瓒婃櫄鑾峰彇瓒婂厛閲婃斁锛侊紒
      //鏈€濂藉皢閲婃斁璧勬簮浠ｇ爜鏀惧湪finally閲? if(resultSet!=null) 
       try 
           resultSet.close();
        catch (SQLException e) 
           e.printStackTrace();
        finally 
           resultSet = null;
       
   
      if(statement!=null) 
          try 
              statement.close();
           catch (SQLException e) 
              e.printStackTrace();
           finally 
              statement = null;
          
      
      if(conn!=null) 
          try 
              conn.close();
           catch (SQLException e) 
              e.printStackTrace();
           finally 
              conn = null;