Logical Query Execution Order
Why FROM runs before SELECT and how knowing the true execution order answers a dozen trick questions.
The Question That Unlocks a Dozen Others
Interviewers ask "In what order does a query actually run?" because it explains so much: why a SELECT alias fails in WHERE, why WHERE can't filter an aggregate, and more.
Written Order vs Logical Order
You write a query starting with SELECT, but the engine runs it starting with FROM. That mismatch, with SELECT evaluated almost last, causes most confusion.
All lessons in this course
- What Is SQL and Why Interviewers Ask It
- Logical Query Execution Order
- Primary Keys, Foreign Keys and Constraints
- Reading a Schema Under Pressure