Partial properties

With C#13, you can now have partial properties, see Microsoft documentation here

In order for you to have partial properties, in your <database.tt> file, find the Settings.UpdateColumn delegate. There is an example of this commented out, but what you want to do is to add something like this:

Settings.UpdateColumn = delegate(Column column, Table table, List<EnumDefinition> enumDefinitions)
{
    ...
    if (table.NameHumanCase.Equals("SomeTable", StringComparison.InvariantCultureIgnoreCase) &&
        column.NameHumanCase.Equals("SomeColumn", StringComparison.InvariantCultureIgnoreCase))
        column.IsPartial = true;
    ...

For the code below, I used

if (table.NameHumanCase.Equals("AbOrderLinesAb", StringComparison.InvariantCultureIgnoreCase) &&
    column.NameHumanCase.Equals("Sku", StringComparison.InvariantCultureIgnoreCase))
    column.IsPartial = true;

Saving the <database.tt> produces:

namespace V9EfrpgTest;
...
public partial class AbOrderLinesAb
{
    public int Id { get; set; } // ID (Primary key)
    public partial string Sku { get; set; } // sku (length: 15)
    ...
}

The above Sku property is now the "declaring declaration".

You also need to create a partial class and a matching "Implementation declaration" property in another file. Here I've created a file named AbOrderLinesAb_partial.cs:

namespace V9EfrpgTest;

public partial class AbOrderLinesAb
{
    private string _sku = string.Empty;
    public partial string Sku
    {
        get => _sku;
        set => _sku = value;
    }
}

If you have a lot of column names you would like to make partial, you can use an array like this:

var makePartial = new List<string> { "createdby", "createdon", "modifiedby", "modifiedon" };
if (makePartial.Contains(column.NameHumanCase.ToLower()))
    column.IsPartial = true;