sql server update field if condition is met

Question

i'm working on a project where i have to alter a tables defenition but i need to keep the data there's already there and i don't know how to accomplish this.

the actual table struct is as follows

[IDDocumento (int)]
[IDTipoDocumento (int)]
[IDEntidade (int)]
[Data (datetime)]
[Designacao (varchar 100)]
[TotalIliquido (money)]
[TotalImposto (money)]
[TotalRetencoes (money)]
[TotalLiquido (money)]
[Anulado (bit)]

what i need to do here is to drop the 'Anulado' column and add 3 new columns, maintaining the stored data, and giving a value to one of the new columns if 'Anulado' was TRUE

what i have is

ALTER TABLE dbo.Documentos
ADD
IDEstadoDocumento int null,
DataVencimento datetime null,
ValorAberto decimal(18,5) not null CONSTRAINT DF_Documentos_ValorAberto DEFAULT 0;

//HERE IS WHERE I NEED TO CHECK IF 'ANULADO' IS TRUE OR NOT AND CHANGE 'IDEstadoDOCUMENTO' TO 3 WHEN IT IS

ALTER TABLE dbo.Documentos
DROP COLUMN Anulado;

How am i suposed to do this?

Answer 1

I simple update should suffice

UPDATE dbo.Documentos SET IDEstadoDocumento = 3 WHERE Anulado = 1