IN Clause with NULL or IS NULL

Question

The DBMS is Postgres. Is it possible to use NULL in an IN clause? example:

SELECT *
FROM tbl_name
WHERE id_field IN ('value1', 'value2', 'value3', NULL)

To these four values only, please. The aforementioned statement executes but fails to add the records with NULL id fields when I run it. I've also attempted to include an OR condition, however, doing so merely makes the query keep running indefinitely.

Can someone please help me with this?

Answer 1

An in statement will be parsed identically to field=val1 or field=val2 or field=val3. Putting a null in there will boil down to field=null which won't work.

(Comment by Marc B)

I would do this for clarity. 

SELECT *
FROM tbl_name
WHERE 
(id_field IN ('value1', 'value2', 'value3') OR id_field IS NULL)