oracle null value in quotes - yet another newbie question
Simple! Put NULL without quotes.

E.g.

INSERT INTO tableName (columnName1, columnName2) VALUES ('Value1', NULL)


We must always use NULL without quotes when we intend to use NULL values. Putting quotes around it, like 'NULL' makes it a string literal and it is treated as character data. Hence for using NULL values, we must always use NULL without quotes, be it a null string, a null number or a null BLOB. For every data type, we must use NULL without quotes.