InvalidOperationException: The LINQ expression-CodePudding

I'm using ef to query to databse my query is to get a date from database (string type), convert it to date type and compare it to another date

 var res = _context.Course.Where(a => DateTime.ParseExact(a.CourseStart, "MM/dd/yyyy", CultureInfo.InvariantCulture) > fromDate).ToList();

and the result is always InvalidOperationException: The LINQ expression 'DbSet() .Where(c => DateTime.ParseExact( s: c.CourseStart, format: "MM/dd/yyyy", provider: __InvariantCulture_0) > __fromDate_1)' could not be translated.

CodePudding user response：

InvalidOperationException: The LINQ expression 'DbSet() .Where(c => DateTime.ParseExact( s: c.CourseStart, format: "MM/dd/yyyy", provider: __InvariantCulture_0) > __fromDate_1)' could not be translated.

The reason is that implicit client evaluation has been disabled from EF Core 3.

You can switch to client evaluation explicitly by inserting a call to AsEnumerable like below:

var res = _context.Course.AsEnumerable()                //add here...
    .Where(a => DateTime.ParseExact(a.CourseStart, "MM/dd/yyyy", CultureInfo.InvariantCulture) > fromDate)
    .ToList();