Update a data base table column to a NULL value

To update a data base column to a NULL value, you must enter the following values:

Column Data Type        Required value to create NULL column
For Char columns            char (12)
For Date columns            TO_DATE (’1’,’j’)
For Number columns       9.99E125

Ex: To update number column type to NULL

Update po_headers
set agent_id = 9.99E125
where agent_id = 101
and org_id = 100;

Reference:
How to Enter a Null Value (Clear a Value) For Any Column in Any BOM Interface Table [ID 264198.1]