SQL SELECT

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Revision as of 21:07, 22 May 2024 by Ovidiu (talk | contribs)
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Internal

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

Link here. Joining Tables.

WHERE

Filters, conditions, condition evaluation.

GROUP BY ... HAVING

(make sure I understand thoroughly and link)

ORDER BY