If Else condition

[Lexxzy]

Hi all,

Does anyone have an ideas on how to use if else condition in creating and altering tables which is not inside the create procedure or function scripts?
For example:
If not exists() then
create table scripts();
else
alter table.....



thanks.

[Civic1986]

if exists( condition )
begin
/// if condition is true then statements to be executed..
end
else
begin
/// if condition is false then statements to be executed..
end