Question

I have a table with no index. I need to add a clustered index on one column but the table does not have any column having unique data.Will this allow me to add clustered index on a duplicate column?

Answer 1

A clustered index does not enforce uniqueness unless you specify the keyword UNIQUE.

CREATE CLUSTERED INDEX bob ON foo( bar )

is not the same as

CREATE UNIQUE CLUSTERED INDEX bob on foo( bar )

You may be thinking of a PRIMARY KEY constraint in a CREATE TABLE statement.
In this example:

CREATE TABLE foo ( bar PRIMARY KEY )

ASE will create a UNIQUE, CLUSTERED index on bar.