Question

Using the ASP.NET Web-Api, I have the following POST setup in my controller. When posting to it from Fiddler, I get the error message:

The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities.

…when it gets to the var auth = dba.ApiMembers… line

    // POST api/Avail
    [BasicAuthentication]
    public HttpResponseMessage PostAvail(Avail[] avail)
    {
        if (ModelState.IsValid)
        {
            // Check if authorised
            var auth = dba.ApiMembers.Where(a => a.hotel_id == 
                   avail[0].HID && a.UserName == User.Identity.Name)
                   .FirstOrDefault();

Can anyone see anything wrong with this line?

Answer 1

LINQ2SQL queries run in database, and it’s not possible to translate User.Identity.Name and avail[0] into database commands. You should initialize those values as parameters and pass simple types to LINQ query.

var hid = avail[0].HID;
var userName = User.Identity.Name;
var auth = dba.ApiMembers.Where(a => a.hotel_id == hid && a.UserName == userName).FirstOrDefault();