Neglect variable from Query in entity framework where condition C#

Question

public ActionResult sortFilteredItem(string sortByValue,string brand,string category,int price=0 )
{
  var sortedData = (dynamic)null;
  if (sortByValue != "")
  {
    if(sortByValue == "ltoh")
    {
      sortedData = DB.Prouducts.where(x=> x.brandName == brand & x.catName == category & x.price == price).ToList();
    }

  }
 return View(sortedData);
}

how i can neglect if price=0 from query means that it does not make any impact on EF query because if price=0 the query does not returning expected output.Because i have not any record that has 0 price so the query is always returning null.

if(price != 0)
{
    sortedData = DB.Prouducts.where(x=> x.brandName == brand & x.catName == category & x.price == price).ToList();
}
else
{
    sortedData = DB.Prouducts.where(x=> x.brandName == brand & x.catName == category).ToList();
}

i have tried like this it is working good but that is lengthy process.if i have 4 or 5 more variable that,s optional so it is necessary to check null value first for working.Any recommendation ?

you don't use and operator correctly IMHO. You should use && instead of & — ilkerkaran
– ilkerkaran, Commented Sep 17, 2019 at 14:30
that,s not problem i always use single & operator so that,s not an issue. issue is only to check null and neglect from query as i asked above. — Shakir
– Shakir, Commented Sep 17, 2019 at 14:34
there is already an answer that will solve your problem AFAIK. But using bitwise operator when you don't mean to compare like that is a bad practice. I did not answer your question. That is why I am putting it here in the comments section. Happy coding — ilkerkaran
– ilkerkaran, Commented Sep 17, 2019 at 14:37
you are right i does not said that you are wrong i just tell to you that is not problem. so you give me suggestion to use && that.s great — Shakir
– Shakir, Commented Sep 17, 2019 at 14:41

ilkerkaran · Accepted Answer · 2019-09-17 14:48:20Z

4

You can use the fllowing logic;

sortedData = DB.Prouducts.where(x=> x.brandName == brand 
    && x.catName == category 
    && (price == 0 || x.price == price)) //use this approach for every optional param
    .ToList();

answered Sep 17, 2019 at 14:48

ilkerkaran

4,3923 gold badges31 silver badges45 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Shakir Over a year ago

same problem again if price=0 the query always return null because i have no any record in DB that has 0 price.

ilkerkaran Over a year ago

@Shakir, this condition does not do that. it is doing like, if input price==0 then (price == 0 || x.price == price) returns true. So if the code above does not work, you should look somewhere elste to solve your problem

Andrei · Accepted Answer · 2019-09-17 14:40:02Z

2

What you can do is apply filters only if the condition holds. Let's say you need to check catName and price. So:

var query = DB.Prouducts.Where(x=> x.brandName == brand);
if (category != null)
{
     query = query.Where(x => x.catName == category);
}

if (price != 0)
{
    query = query.Where(x => x.price == price)
}

sortedData = query.ToList();

Obviously you'll need one "if" per filter, but it is much better than considering all possible combinations.

edited Sep 17, 2019 at 14:40

answered Sep 17, 2019 at 14:29

Andrei

56.8k10 gold badges92 silver badges114 bronze badges

2 Comments

Shakir Over a year ago

so that is lengthy process if i have to check 4 to 5 variables null.so i have to check like this if(brandName != "" & catName != "" & price != ""){ some code}and so on it will make 5 to 6 condtions that,s is real proble.

Andrei Over a year ago

@Shakir, perhaps i didn't explain the answer well enough. see update

Collectives™ on Stack Overflow

Neglect variable from Query in entity framework where condition C#

2 Answers 2

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related