Linq to EF with Sqlite - Can't Search String (string.contains)

I am building a winforms desktop application and the app DB is Sqlite. I am using Linq to Entities with the Sqlite ADO.NET provider.

In my app I need to search a string inside a text column. Example ("IsNotEmpty" is my extension method for !string.IsNullOrEmpty(str)):

        if (param.FirstName.IsNotEmpty())
        {
            selectedCustomers = selectedCustomers.Where(c => (c.firstName.Contains(param.FirstName)));
        }
        if (param.LastName.IsNotEmpty())
        {
            selectedCustomers = selectedCustomers.Where(c => c.lastName.Contains(param.LastName));
        }

The problem 开发者_JS百科is that this query is being translated to CHARINDEX SQL function and Sqlite doesn't support it.

When I am switching to IndexOf(string) function (as suggested here) the query is being translated to CHARINDEX too.

When I am switching to IndexOf(string, index) I receive the following error:

LINQ to Entities does not recognize the method 'Int32 IndexOf(System.String, Int32)' method, and this method cannot be translated into a store expression.

Any idea? Should I switch to Access?

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You can't use .NET functions in LINQ to Entities its because of security, e.g. IndexOf() may do lot of other things than just checking the string.

Use Entity SQL http://msdn.microsoft.com/en-us/library/bb738683.aspx instead.