Search⌘ K
AI Features
Home
Courses
SQL Antipatterns: Avoiding the Pitfalls of Database Programming

Synopsis: Rounding Errors

Explore how rounding errors occur in SQL calculations using FLOAT data types for fractional numbers. Understand why inaccuracies happen in cost reports, the impact of data types on arithmetic precision, and the importance of choosing the correct numeric type for accurate database computations.

We'll cover the following...

Let’s imagine that your boss asks you to produce a report of the cost of programmer time for the project, based on the total work needed to fix each bug. Each programmer in the Accounts table has a different hourly rate, so you record the number of hours required to fix each bug in the Bugs table, and you multiply it by the hourly_rate of the programmer assigned to do the work.

MySQL
SELECT b.bug_id, b.hours * a.hourly_rate AS cost_per_bug
  FROM Bugs AS b 
  JOIN Accounts AS a ON (b.assigned_to = a.account_id);

It would be best to create ...