July 2021
Intermediate to advanced
336 pages
10h 56m
Polish
Content preview from Wprowadzenie do SQL
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Rozdział 13. Indeksy i ograniczenia
Ponieważ w tej książce skoncentrowałem się na technikach programistycznych, pierwszych dwanaście rozdziałów dotyczyło elementów języka SQL, które pozwalają tworzyć zapytania SELECT, INSERT, UPDATE i DELETE. Jednak inne funkcje bazy danych pośrednio wpływają na tworzony kod. W tym rozdziale skoncentrujemy się na dwóch spośród tych funkcji, czyli na indeksach i ograniczeniach.
Indeks
Gdy wstawiasz rekord do tabeli, serwer bazy danych nie próbuje umieścić danych w żadnym konkretnym miejscu tabeli. Dlatego na przykład podczas dodawania rekordu do tabeli customer serwer nie umieszcza go w kolejności liczbowej według wartości kolumny customer_id bądź alfabetycznej według wartości kolumny last_name, lecz w pierwszym ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.