Turn any data source into an IQueryable
C#
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.

README.md

Linq To Anything

Install-Package LinqToAnything

This bombastically titled library is, in a nutshell, an IQueryable wrapper for your non-iqueryable (but pageable) data access methods, be they stored procedures or web requests or whatever.

Take one paged data access method:

    
    public void IEnumerable<Product> GetProductsFromSproc(int skip, int take, string category) { ... };
	public void IEnumerable<Product> GetCountOfProductsInCategoryFromSproc(int skip, int take, string category) { ... };
    
    class Product{
        public string Id {get;set;}
        public string Name {get;set;}
        public int Price {get;set;}
        public string Category {get;set;}
    }

Wrap it as a Func<QueryInfo, object*> delegate. ** note that


    Func<QueryInfo, IEnumerable<Product>> wrapper = queryInfo => {

        //extract the category value from the query info object
        var category = queryInfo.Clauses.OfType<Where>()
            .Where(c => c.PropertyName == "Category" && c.Operator == "Equals")
            .Select(c => c.Value);
		
		if (queryInfo.Clauses.OfType<CountClause.Any())
			return GetCountOfProductsInCategoryFromSproc(category);

        return GetProductsFromSproc(queryInfo.Take, queryInfo.Skip, category);
    };


    //Now we can create our queryable using the wrapper delegate
    IQuerable<Product> queryable = DelegateQueryable<Product>.Create(wrapper);

Basically, the queryInfo object provides a simplified view of the expression tree which you can then map to your data source: A QueryInfo object contains:

  • a Take, a Skip and an OrderBy property
  • an enumerable of Clause objects (Wheres, or Ors).

Please see QueryInfo.cs for info on what queries are supported, and what operators you can use.

It makes it easy to disassemble and reconstruct Linq queries, so you can do custom stuff to them, like: