Exact difference between primary key and unique + not nul
what is the difference between primary key column and not null + unique column.
I know one difference is a table can have only one primary key and any number of not null + unique key columns.
I think the functionality is same for the both type of columns.
Any other differences that you know??
clustered index for primary key doubt?
I heard that a clustered index will be created automatically
for primary key. As per my knowledge cluster means combination of two common columns of two tables. But how does a primary key creates the
cluster index? for which cluster it creates the index?