Foreach statements returning incorrect results - Linq to SQL

Question

User940894612 posted

Hi All

I'm having a slight issue.  Please see code below.  I should only be returning 4 records from my feedback table and adding the comments to the relevant panel depending on whether it is divisible by 2.  

However, I am getting 16 records appearing in the front end and I'm not sure why. a quick debug seems to show that it executes the select statement which returns the 4 records and then does my foreach statement on all of them.  

I essentially want it to get one record and then display the relevant comments, then get the second record and do the same and third, fourth etc.  Any ideas on where I have gone wrong? 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Testimonials1 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        AltanaDataClassesDataContext db = new AltanaDataClassesDataContext();

        var testimonials = from t in db.Feedbacks
            where t.OnSite == true
            select t;

        int count = testimonials.Count();
        foreach (var tesimonial in testimonials)
        {

            for (int i = 0; i < count; i++)
            {
                int y = i % 2;

                if (y == 0)
                {
                    Literal literal = new Literal();
                    literal.Text = "<div class='row'><div class='col-lg-6'>0" + Server.HtmlDecode(tesimonial.Comments) + "</div>";
                    pnlTestimonials.Controls.Add(literal);
                }
                else
                {
                    //Response.Write(y + " b ");
                    Literal literal = new Literal();
                    literal.Text = "<div class='col-lg-6'>1 " + Server.HtmlDecode(tesimonial.Comments) + "</div></div>";
                    pnlTestimonials.Controls.Add(literal);
                }
            }
        }
    }
}

Thanks

Rob

Answer 1

User475983607 posted

That are two nested loops code so you end up with X^2 iterations.  Remove one of the loops.

        int count = testimonials.Count();  
        foreach (var tesimonial in testimonials)  //LOOP 1
        {

            for (int i = 0; i < count; i++) // LOOP 2
            {

Answer 2

User940894612 posted
Hi

Thanks for your response, can you show me how please?

Thanks
Rob

Answer 3

User940894612 posted

For example below:

for (int i = 0; i < testimonials.Count(); i++) 
{ 
int y = i % 2; if (y == 0) 
{ 
Literal literal = new Literal(); literal.Text = "

0" + Server.HtmlDecode(tesimonial.Comments) + "
"; pnlTestimonials.Controls.Add(literal); } else { Literal literal = new Literal(); literal.Text = "
1 " + Server.HtmlDecode(tesimonial.Comments) + "
"; pnlTestimonials.Controls.Add(literal); 
} 
}

How can I get the testimonial.Comment value as its not avaiable to me anymore?

Thanks

Rob

Answer 4

User1520731567 posted

Hi Robbied81,

Robbied81

foreach (var tesimonial in testimonials)
        {

            for (int i = 0; i < count; i++)
            {
                int y = i % 2;

According to your code:

Nested loop in loop,Record will increase exponentially

If you would like to filter even and odd lines,you could:

int i = 0;
foreach (var tesimonial in testimonials)
{
  if(i%2==0)
  {}
  else
  {}

  ++i;
}

Best Regards.

Yuki Tao