Question

I have a database table that holds order information and saves the current gold price (world price) automatically at the time of entry.

If I look back on the table, and the saved gold price has a difference with the current gold price of +100, O want to show that in a report.

How would I write the MySQL query to do this? I know how to do datediffs but not numeric values.

Example:

select * from table where saved_price < current_price - 100

Is there a better way to do this?

Answer 1

Use Abs if the sign of the difference doesn’t matter:

select * from table where abs(saved_price - current_price) > 100

If the sign is interesting, your suggested approach is fine. I’d write it like this, but use the way you think is the most read- and understandable:

select * from table where (current_price - saved_price) >= 100