Revision
Comparisons with NULL
10. Never trust a NULL
Functions with NULL
COALESCE to the rescue
NULLIF
Revision and practice

## Instruction

Good! As you can see, you need to keep your eyes open when you work with NULLs in your WHERE statements.

Remember – every time, think whether some columns can be NULLs. If they can, modify your query a tiny bit, just as we did in this section.

## Exercise

Press to continue.

Code editor

TableConsole