first.java~4~

来自「学生信息管理系统」· JAVA~4~ 代码 · 共 78 行

package sfms;


import java.sql.*;

public class first{
  public static void main(String args[]){
    //declare Connection and Statement objects
    Connection conn=null;
    Statement state=null;
    try{
      //register the Oracle JDBC drivers
      Class.forName("oracle.jdbc.OracleDriver").newInstance();
      //create a Connection object,and connect to the database
      //as df using the Oracle JDBC thin driver
      conn=DriverManager.getConnection(
          "jdbc:oracle:thin:@localhost:1521:SFMS",
          "df","1234"
          );
      //create a Statement object
      state=conn.createStatement();

      //create a ResultSet object,and populate it with the
      //result of SELECT statement that retrieves the user
      //and sysdate variables from the database via the dual
      //table -the executeQuery() method of the Statement object
      //is used to perform the SELECT
      ResultSet result=state.executeQuery(
          "SELECT user,sysdate from dual"
          );

      //
      //the next() method
      result.next();

      //retrieve the user from the row in the Resultset using
      //the getString() method
      String user=result.getString("user");

      //retrieve the sysdate from the row in the ResultSet using
      //the getTimestamp() method
      Timestamp dateTime=
          result.getTimestamp("sysdate");

      System.out.print("Hello  "+user+
                       ", the current date and time is "+dateTime);

      //close this ResultSet object using the close() method
      result.close();
    }
    catch(SQLException e){
      System.out.println("Error Code ="+e.getErrorCode());
      System.out.println("Error message="+e.getMessage());
    }
    catch(Exception e){
        e.printStackTrace();
      }

    finally{
      try{

        //close the Statement object using the close() method
        if(state!=null){
         state.close();
        }
        //close the Connection object using the close() method
        if(conn!=null){
          conn.close();
        }
      }
      catch(SQLException e){
        System.out.println("Error Code ="+e.getErrorCode());
       System.out.println("Error message="+e.getMessage());
      }
    }
  }//end of main()
}