Argument data type xml is invalid for argument 1 of Len Function

Question

I am mapping a property to the xml database using Migrations.

public string Xml { get; set; }

this.Property(t => t.Xml).HasColumnName("Xml").HasColumnType("xml");

However, when consulting the class using Linq returns the error.

 _context.PreListaPostagemLog.Where(p => p.IdPlp == null && !string.IsNullOrEmpty(p.Xml)).ToList();

Argument data type xml is invalid for argument 1 of Len Function.

Answer 1

In SQL Server, len() does not work with XML type. You’ll need to use datalength() in place.

In the Entity Framework, datalength() wears like this:

_context.PreListaPostagemLog
        .Where(p => p.IdPlp == null && SqlFunctions.DataLength(p.Xml) > 0)
        .ToList();

See more about SqlFunctions here.