/* In order to show example of IFNULL or COALESCE, we would need NULL values in our dataset. So, I have decieded to change dep_duplicate table. */ Alter table dep_duplicate change column dept_name ...

IFNULL is a MySQL variant (also used in other DBs) which takes only 2 arguments and returns the first one that is not null. Closes: #35749 ...

In MySQL, the IFNULL operator is used as conditional statement for NULL values. When we need to fetch NULL values with LIKE operator then we can use this operator.