SQLite add Primary Key

I created a table in Sqlite by using the CREATE TABLE AS syntax to create a table based on a SELECT statement. Now this table has no primary key but I would like to add one. Executing ALTER TABLE table_name ADD PRIMARY KEY(col1, col2,...) gives a syntax error "near PRIMARY" Is there a way to add a primary key either during table creation or afterwards in Sqlite? By "during creation" I mean during

[hayashih]

“http://sqlite.org/faq.html#q11”