Instruction
Nicely done! Now it's time to review what we've learned:
- The
IS NULLoperator checks if a column value isNULL. - The
IS NOT NULLoperator checks if a column value is notNULL. COALESCE(x, y, ...)returns the first non-NULL argument or replaces aNULLwith the value given in the second argument.- The
GREATEST()andLEAST()functions return the largest and the smallest value among values in the argument list, respectively. - The
NULLIF(x, y)function returnsNULLifx = y. Otherwise, it returnsx.
Are you ready for a short quiz?
Exercise
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