Question

For a website I’m doing we’re using LINQ to Entities. I have been charged with adding search functionality to the site. I’m trying to figure out the most elegant way to search for multiple keywords (user entered) on a single field in the database. Allow me to give an example.

Table columns:

Name, Description 

Example row:

'Cookie monster', 'Fluffy, likes cookies and blue' 

User search (delimiter doesn’t matter):

'blue fluffy'  

Currently I am using the following:

    public List<SesameCharacters> SearchByKeywords(string keywords)     {         List<SesameCharacters> output = new List<SesameCharacters>();         string[] k = keywords.ToLower().Split(' ');         using (SesameStreet_Entities entities = new SesameStreet_Entities())         {             IQueryable<SesameCharacters> filter = entities.SesameCharacters;              foreach (string keyword in k)                 filter = ForceFilter(filter, keyword);              output = filter.ToList();         }         return output;     }      private IQueryable<SesameCharacters> ForceFilter(IQueryable<SesameCharacters> filter, string keyword)     {         return filter.Where(p => p.Description.ToLower().Contains(keyword));     } 

This currently works as expected but I imagine it is not the best solution to the problem. Am I missing something glaringly obvious?

NOTE: This is AND matching.

Answer 1

Looks like Linq to Entities doesn’t support contains:

http://msdn.microsoft.com/en-us/library/bb738638.aspx

I’d roll my own query for this one. Your probably going to want full control over the text search queries if you find out these types of searches become performance issues.