select distinct T1."order_number" as "Order Number",
	   T1."invoice_number" as "Invoice Number_ohne_type",
	   T2."invoice_type" as "Invoice Type",
	   (substring((convert(varchar(50), T2."invoice_type")), 1, 1)) + (substring((convert(varchar(50), T1."invoice_number")), 1, 6)) as "Invoice Number"
from ("dbo"."invoices" T2 left outer join "dbo"."labours" T1 on (T1."invoice_number" = T2."invoice_number") and (T1."invoice_type" = T2."invoice_type"))
where (((substring((convert(varchar(50), T2."invoice_type")), 1, 1)) + (substring((convert(varchar(50), T1."invoice_number")), 1, 6))) <> '')
-- order by "Order Number" asc