Why is using '*' to build a view bad?

Question

Why is using \'*\' to build a view bad ?

Suppose that you have a complex join and all fields may be used somewhere.

Then you just have to chose fields needed

Answer 1

These other answers all have good points, but on SQL server at least they also have some wrong points. Try this:

create table temp (i int, j int)
go
create view vtemp as select * from temp
go
insert temp select 1, 1
go
alter table temp add k int
go
insert temp select 1, 1, 1
go
select * from vtemp

SQL Server doesn't learn about the "new" column when it is added. Depending on what you want this could be a good thing or a bad thing, but either way it's probably not good to depend on it. So avoiding it just seems like a good idea.

To me this weird behavior is the most compelling reason to avoid select * in views.

The comments have taught me that MySQL has similar behavior and Oracle does not (it will learn about changes to the table). This inconsistency to me is all the more reason not to use select * in views.