SQLite: Do I need to create an index on primary key autoincrement field?

Question

PHP

SQLite.
There is a field:
id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL
Do I need to create an index?
CREATE UNIQUE INDEX c_id ON categories (id)

Answer 1

The PRIMARY KEY is always created through the creation of a UNIQUE INDEX. So you don't need to create an additional index.

Answer 2

not necessary