Linq query return 1 item instead of all

Question

I am using the query below to grab all records that have a SubCategoryName == subCatName and i want to return all of there ProductID's as a list of ints. Problem is when my code runs it is only returning 1 int(record) instead of all. How can i make it return all of the records that have that subCatName? Its returning a count = 1 with a capacity of 4. So it is a int[4] but only the first [0] is = to a actual product ID the rest returning zero?

   public List<int> GetPRodSubCats(string subCatName)
    {
        var _db = new ProductContext();

        if (subCatName != null)
        {
            var  query = _db.ProductSubCat
                            .Where(x => x.SubCategory.SubCategoryName == subCatName)
                            .Select(p => p.ProductID);

            return query.ToList<int>();
        }
        return null;
    }

Your code looks fine. Are you 100% sure your query doesn't just return 1 row? — Daniel Kelley, Mar 01 '13 at 16:25
You sure you have more than one result to return anyway? Try using Linqpad to test things out (http://www.linqpad.net/) — Matthew Watson, Mar 01 '13 at 16:26
Make sure that your database has more than one record for that subcategory :) — Sergey Kalinichenko, Mar 01 '13 at 16:26
@DanielKelley I looked in the Database and there is multi records that fit my params. It is like it is only grabbing the first record. — jackncoke, Mar 01 '13 at 16:50
It was right. It turns out to that it was another method causing the problem. — jackncoke, Mar 04 '13 at 16:49

Stan R. · Answer 1 · 2013-03-01T17:02:44.283

2

This seems more like an expected behavior here. How do you know you don't only have 1 record that satisfies the Where predicate.

Your code is correct, however you might want to normalize your comparison.

x => x.SubCategory.SubCategoryName == subCatName

to use a specific case for instance:

x => x.SubCategory.SubCategoryName.ToLower() == subCatName.ToLower()

you might also consider a Trim.

edited Mar 01 '13 at 17:02

answered Mar 01 '13 at 16:28

Stan R.

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Tim Schmelter · Accepted Answer · 2013-03-01T16:39:09.140

2

As Daniel already has mentioned, the code should work. But maybe you are expecting that it's case-insensitive or ignores white-spaces. So this is more tolerant:

subCatName = subCatName.Trim();
List<int> productIDs = _db.ProductSubCat
     .Where(x => String.Equals(x.SubCategory.SubCategoryName.Trim(), subCatName, StringComparison.OrdinalIgnoreCase))
     .Select(p => p.ProductID)
     .ToList();

edited Mar 01 '13 at 16:39

answered Mar 01 '13 at 16:31

Tim Schmelter

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The class name "Context" and the variable name "_db" indicates that he is using Entity Framework. In this case your code won't work because it can't be translated to an SQL statement. – JustAnotherUserYouMayKnow Mar 01 '13 at 16:33
@JustAnotherUserYouMayKnow: Overlooked it somehow. `String.Equals` on the other hand should work as this answer suggests: http://stackoverflow.com/a/841342/284240 – Tim Schmelter Mar 01 '13 at 16:39
This will result in an ArgumentException "Incorrect number of arguments supplied for call to method 'Boolean Equals(System.String, System.String, System.StringComparison)'" when enumerating the query. Stans answer works, also when you add an ".Trim()" before or after the ".ToLower()". This was tested with EntityFramework 4. The stackoverflow answer you linked refers to linq-to-sql, not linq-to-entities. It all depends on what framework he is actually using. ;-) – JustAnotherUserYouMayKnow Mar 01 '13 at 16:54

Linq query return 1 item instead of all

2 Answers2