Linq query to sort strings like numbers in ASP.NET-Core 3.0 and above-CodePudding

I've recently upgraded from ASP.NET-Core 2.2 to ASP.NET-Core 3.1. I have quantities that are strings (most are just numbers but we have some that are 100 Feet, 1 Spool, etc...) In 2.2 I could sort these by using PadLeft, but this throws an error in ASP.NET-Core3.0 and above. Does anyone know a good workaround for using LINQ queries which sort numbers that are strings? (so you don't get "999", then "99", then "888", "88", etc...)

My old solution was:

  IQueryable<InventoryItem> Items;
  Items = from m in _context.Inventory.Where(m => m.Removed == 0)
                                              select m;
    case "Quantity":
         Items = Items.OrderByDescending(s => s.Quantity.PadLeft(maxlen, '0'));
         break;

This no longer works because ASP.NET-Core 3.1 evaluates it at the server instead of at client. It doesn't understand .PadLeft()

Added: I am paginating, so the query is running on this line:

 items = await source.Skip(
                    (pageIndex - 1) * pageSize)
                    .Take(pageSize).ToListAsync();

If I go toList before then, I'm not limiting the results from the query to the number of results chosen...

CodePudding user response：

You have an error because Linq can't convert your code to Sql query. So you have to download data from db at first using ToList (or ToArray) for example. After this you can use any kind of algorithm to sort the list.

Items = _context.Inventory.Where(m => m.Removed == 0).ToList();

Items = items.OrderByDescending(s => s.Quantity.PadLeft(maxlen,'0'));

CodePudding user response：

Try to do this. Convert.ToInt32 is automatically converted from EF into a query.

Items = Items.OrderByDescending(s => Conert.ToInt32(s.Quantity));