Ðàçðàáîòêà áàç äàííûõ â Delphi. 11 Óðîêîâ

         

 BETWEEN


Ïðåäèêàò BETWEEN çàäàåò äèàïàçîí çíà÷åíèé, äëÿ êîòîðîãî âûðàæåíèå ïðèíèìàåò çíà÷åíèå true. Ðàçðåøåíî òàêæå èñïîëüçîâàòü êîíñòðóêöèþ  NOT  BETWEEN.

SELECT first_name, last_name, salary

FROM employee

WHERE salary BETWEEN 20000 AND 30000
                          ïîëó÷èòü ñïèñîê ñîòðóäíèêîâ,
                                                                       ãîäîâàÿ çàðïëàòà êîòîðûõ
                                                                       áîëüøå 20000 è ìåíüøå 30000

FIRST_NAME      LAST_NAME           SALARY

=============== ========== ===============

Ann             Bennet            22935.00

Kelly           Brown             27000.00

Òîò æå çàïðîñ ñ èñïîëüçîâàíèåì îïåðàòîðîâ ñðàâíåíèÿ áóäåò âûãëÿäåòü ñëåäóþùèì îáðàçîì:

SELECT first_name, last_name, salary

FROM employee

WHERE salary >= 20000

  AND salary <= 30000     ïîëó÷èòü ñïèñîê ñîòðóäíèêîâ,
                                                                       ãîäîâàÿ çàðïëàòà êîòîðûõ
                                                                       áîëüøå 20000 è ìåíüøå 30000

FIRST_NAME      LAST_NAME           SALARY

=============== ========== ===============

Ann             Bennet            22935.00

Kelly           Brown             27000.00

Çàïðîñ ñ ïðåäèêàòîì BETWEEN ìîæåò èìåòü ñëåäóþùèé âèä:

SELECT first_name, last_name, salary

FROM employee

WHERE last_name BETWEEN "Nelson" AND "Osborne"
                           ïîëó÷èòü ñïèñîê ñîòðóäíèêîâ,
                                                                         ôàìèëèè êîòîðûõ íà÷èíàþòñÿ
                                                                         ñ “Nelson”
                                                                         è çàêàí÷èâàþòñÿ “Osborne”

FIRST_NAME      LAST_NAME                 SALARY

=============== =============== ================

Robert          Nelson                 105900.00

Carol           Nordstrom               42742.50




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