query xml string using LINQ

Question

I have a table like this

Table (Id decimal,XMLContent XML)

now I want to query records that have specific Type this is my Code

 public ActionResult Index(int? id,FormCollection frm)
    {

        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        ViewBag.FormId = id;
        ViewBag.FormName = db.Forms.Find(id).Name ;
        var xMLDatas = db.XMLDatas.Include(x => x.Form).Where(x=>x.FormId==id).AsQueryable();
        foreach (string item in frm)
        {
            if (item.StartsWith("xml-") && !string.IsNullOrEmpty( Request.Form[item]))
            {
                string i = item.Replace("xml-", "");
                string value = Request.Form[item];
                xMLDatas = xMLDatas.Where(x => x.XMLContent.Contains("<" + i + "[^>]*>"+value+"</" + i + ">")).AsQueryable();
            }

        }
        return View(xMLDatas.ToList());
    }

but I got this error message on return

Disallowed implicit conversion from data type xml to data type nvarchar, table 'dbo.XMLDatas', column 'XMLContent'. Use the CONVERT function to run this query.

Answer 1

You can't call Contains("<" + i + "[^>]*>"+value+"</" + i + ">")) on XMLContent as sql type for that column is XML and not NVARCHAR .

Basically you can call Contains on something that is a string or implicitly converted to string by SQL Server.

But you can try to work around it on server side. Try to load XML from the DB first:

var xMLDatas = db.XMLDatas.Include(x => x.Form).Where(x=>x.FormId==id).ToList();