SQL-FUNDAMENTALS5 MIN READ
Clause-order pocket guide
Recall the job and timing of core SELECT clauses.
FWGHSOL What is the practical SELECT pipeline? I can use the SELECT alias in WHERE because I just defined it. Correction Use the expression in WHERE, or create the alias in a subquery and filter in the outer query. WHERE runs before SELECT aliases exist. It aligns the filter with the stage where the value exists. WHERE versus HAVING Ask whether the condition is true for one row or one group. Why is LIMIT without ORDER BY risky? It trims an unspecified order, so top, latest, or first is not guaranteed. Add a deterministic ORDER BY with a tie-breaker.
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