i have the following table:

CREATE TABLE dbo.Invoices ( [InvoiceCode] varchar(20), [ParentInvoiceCo de] varchar(20),
[InvoiceDate] date )
INSERT INTO dbo.Invoices
VALUES
( 'INV-001', 'INV-001', N'2015-01-01 00:00:00.000' ),
( 'INV-002', 'INV-001', N'2015-01-01 00:00:00.000' ),
( 'INV-003', 'INV-001', N'2015-01-01 00:00:00.000' ),
( 'INV-004', 'INV-004', N'2015-01-01 00:00:00.000' ),...