package lab6;

import java.sql.*;
import com.microsoft.sqlserver.jdbc.SQLServerResultSet;

public class CachedRowSetExample {

   public static void main(String[] args) {



      // Declare the JDBC objects.
      Connection con = null;
      Statement stmt = null;
      ResultSet rs = null;

      try {

    	  Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

  		String connectionUrl = "jdbc:sqlserver://localhost:1433;"
  				+ "databaseName=NORTHWND;user=Bartek;password=q1w2e3r4;";
  		con = DriverManager.getConnection(connectionUrl);
         // Create and execute an SQL statement that returns a large
         // set of data and then display it.
         String SQL = "SELECT * FROM Customers;";
         stmt = con.createStatement(SQLServerResultSet.TYPE_SS_SERVER_CURSOR_FORWARD_ONLY, +
               SQLServerResultSet.CONCUR_READ_ONLY);

         // Perform a fetch for every row in the result set.
         rs = stmt.executeQuery(SQL);
         timerTest(1, rs);
        // rs.beforeFirst();
//         while(rs.next())
//         {
//
//       	  	System.out.println(rs.getString(1));
//         }
         rs.close();

//         // Perform a fetch for every tenth row in the result set.
//         rs = stmt.executeQuery(SQL);
//         timerTest(10, rs);
//         rs.close();
//
//         // Perform a fetch for every 100th row in the result set.
//         rs = stmt.executeQuery(SQL);
//         timerTest(100, rs);
//         rs.close();
//
//         // Perform a fetch for every 1000th row in the result set.
//         rs = stmt.executeQuery(SQL);
//         timerTest(1000, rs);
//         rs.close();
//
//         // Perform a fetch for every 128th row (the default) in the result set.
//         rs = stmt.executeQuery(SQL);
//         timerTest(0, rs);
//         rs.close();

      }
      // Handle any errors that may have occurred.
      catch (Exception e) {
         e.printStackTrace();
      }

      finally {
         if (rs != null) try { rs.close(); } catch(Exception e) {}
         if (stmt != null) try { stmt.close(); } catch(Exception e) {}
         if (con != null) try { con.close(); } catch(Exception e) {}
      }
   }

   private static void timerTest(int fetchSize, ResultSet rs) {
      try {

         // Declare the variables for tracking the row count and elapsed time.
         int rowCount = 0;
         long startTime = 0;
         long stopTime = 0;
         long runTime = 0;

         // Set the fetch size then iterate through the result set to
         // cache the data locally.
         rs.setFetchSize(fetchSize);
         startTime = System.currentTimeMillis();
         while (rs.next()) {
            rowCount++;
           System.out.println(rs.getString(2));

         }
         stopTime = System.currentTimeMillis();
         runTime = stopTime - startTime;

         // Display the results of the timer test.
         System.out.println("FETCH SIZE: " + rs.getFetchSize());
         System.out.println("ROWS PROCESSED: " + rowCount);
         System.out.println("TIME TO EXECUTE: " + runTime);
         System.out.println();

      } catch (Exception e) {
         e.printStackTrace();
      }
   }
}