What is query execution order conceptually?

< 1 min read

Conceptually, SQL reads top-to-bottom but executes in a different logical order.
The database first identifies the data source, then filters, then aggregates, and finally displays.
Execution order: FROM → JOIN → WHERE → GROUP BY → HAVING → SELECT → ORDER BY → LIMIT.
In a reporting task, I filtered active customers in WHERE before aggregation so counts stayed accurate.
HAVING I used only for aggregated filters like “customers with >5 orders”.
Understanding this helped me fix a bug where alias from SELECT wasn’t working in WHERE.
I moved that condition into a subquery because SELECT runs later.
So I design queries based on logical execution, not written order.

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