Question

I have a blog application that models a database using Entity Framework. The problem with this blog is that it has become difficult to find things I’m looking for. It needs a search function, but I’m not sure how to implement this with SQL and/or LINQ to Entities.

Right now I am searching my database with this LINQ query but it seems like it should be better.

    public IEnumerable<BlogPost> SearchBlogPosts(string query, int page, int itemsPerPage)
    {
        var result = _dataContext.BlogPosts
            .Where(BlogPostContains(query))
            .OrderByDescending(x => x.PostedDate)
            .Skip((page - 1) * itemsPerPage)
            .Take(itemsPerPage),
        return result;
    }

    private Func<BlogPost, bool> BlogPostContains(string query)
    {
        return x => x.Title.Contains(query) || x.Body.Contains(query) || x.Author.Contains(query);
    }

One big problem with this is that the search is case sensitive.

Question 1) Is there a better way to do searching with LINQ to Entities?

Question 2) What about with just plain SQL? How would I write a search stored procedure in SQL Server so that I can map and use that in EF instead of LINQ?

I just want a case-insensitive search that is performed in the database so as to maintain good performance.

Thanks in advance.

Answer 1

The standard approach for this would be a SQL fulltext search. You will have to enable fulltext on the DB, designate column(s) to be fulltext indexed and then will then be able to use SQL Contains queries using these columns.

Fulltext search queries are currently not supported by Linq to Entities – you will have to resort to standard SQL queries for this. You can use ExecuteStoreQuery() to at least map the search results to typed result.