NOT NULL

How to Resolve ORA-01442: column to be modified to NOT NULL is already NOT NULL

by Ed Chen
December 25, 2019December 26, 2019

ORA-01442 ORA-01442 means that the target column is already NOT NULL, you don't have to add it again by modifying the column. I know sometimes… Read More »

How to Resolve ORA-01400: cannot insert NULL into

by Ed Chen
November 27, 2019January 17, 2020

ORA-01400 ORA-01400 means that there's a column which was found as NOT NULL is not listed in the INSERT statement, you have to provide a… Read More »

How to Add or Drop NOT NULL Constraint

by Ed Chen
November 23, 2019January 8, 2020

Add NOT NULL Constraint As I mentioned in How to Resolve ORA-00904 for ALTER TABLE ADD CONSTRAINT, NOT NULL is a constraint, but it's more… Read More »

ORA-00904 Invalid Identifier - Oracle Database Object Name Recognition Examples

How to Resolve ORA-00904 Invalid Identifier

by Ed Chen
March 12, 2019February 20, 2020

ORA-00904 ORA-00904 means that you used an invalid identifier which is mostly an unmatched column name or used an incorrect or unqualified syntax in your… Read More »