SQL SELECT

Internal

• SQL

Overview

Query execution. SQL optimizer. Subqueries.

SELECT FROM WHERE GROUP BY HAVING ORDER BY 

Select all (possibly across multiple tables) then filter and discard with where.

Clauses

FROM

FROM permanent|derived|temporary|virtual(view)

Table alias.

Multiple Tables

Querying Multiple Tables

WHERE

Filters, conditions, condition evaluation.

GROUP BY ... HAVING

(make sure I understand thoroughly and link)