The COALESCE function returns the first non-NULL value from a list of arguments. It is useful for handling NULL values in your data.

Example: Using COALESCE

SELECT Name, COALESCE(City, 'Unknown City') AS City
FROM FreedomFighters;

Do's and Don'ts

Do's

• Use COALESCE to handle NULL values effectively.
• Provide meaningful default values when possible.

Don'ts

• Don't use COALESCE with values that should remain NULL for data integrity.
• Don't list too many arguments without necessity; keep it simple.