I am trying to make search function in my project.

Currently, I want to convert decimal value to string for comparing with searchString.

When I put like this:

```
public ActionResult Search(string searchString)
    {

        var product = from a in _db.Product.Include(a => a.Category)
                      select a;
        if (!String.IsNullOrEmpty(searchString))
        {
            product = product.Where(a => a.model.ToUpper().Contains(searchString.ToUpper())
                               || Convert.ToInt32(a.displaySize).ToString().Contains(searchString));
        }
        return View(product.ToList());
    }

```

It has error, 

> 
> 'LINQ to Entities does not recognize the method 'System.String
>  ToString()' method'.
> 
> 
> 

How can I compare decimal value with string value?

Could you help me?

Thanks.