Cellwise · SQL track

Calculations and missing values

Do maths in a query, and handle NULL.

You can calculate in SELECT, just like in a cell. One trap: in SQLite, an integer divided by an integer drops the fraction, so 7 / 2 is 3. Write 12.0 instead of 12 to keep the decimals.

NULL means “no value”. Any maths with NULL gives NULL, so COALESCE(value, 0) swaps a NULL for something you can use.

What you’ll do

• Work out monthly pay
• Replace missing values
• Work out each share