LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

Question

I\'m migrating some stuff from one mysql server to a sql server but i can\'t figure out how to make this code work:

using (var context = new Context())
{
            


        

Answer 1

Just save the string to a temp variable and then use that in your expression:

var strItem = item.Key.ToString();

IQueryable pages = from p in context.pages
                           where  p.Serial == strItem
                           select p;

The problem arises because ToString() isn't really executed, it is turned into a MethodGroup and then parsed and translated to SQL. Since there is no ToString() equivalent, the expression fails.

Note:

Make sure you also check out Alex's answer regarding the SqlFunctions helper class that was added later. In many cases it can eliminate the need for the temporary variable.