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}); </script> </div> </center> <table border=0 cellspacing=5 class="main-content"><tr><td> <table width=100%><tr><td></td></tr></table> <p>SQL (Structured Query Language) ist eine Computersprache zum Speichern, Bearbeiten und Abfragen von Daten in relationalen Datenbanken. Eine erste Version von SQL erschien 1974, als eine Arbeitsgruppe bei IBM den ersten Prototyp einer relationalen Datenbank entwickelte. Die erste kommerzielle relationale Datenbank wurde von Relational Software (der späteren Firma Oracle) auf den Markt gebracht. <p>Für SQL sind Standards definiert. Dennoch gibt es Unterschiede bei der für die wichtigsten relationalen Datenbank-Managementsysteme jeweils verwendeten SQL. Dies hat zwei Gründe: 1) der SQL-Standard ist relativ komplex und eine Implementierung des kompletten Standards somit oft nicht praxisgerecht und 2) jeder Datenbankanbieter möchte sein Produkt auf irgendeine Weise von den Mitbewerbern abgrenzen. Falls erforderlich, wird in diesem Tutorial auf solche Unterschiede hingewiesen. <p>Das vorliegende SQL-Tutorial führt häufig verwendete SQL-Befehle auf und ist in folgende Abschnitte unterteilt:</p> <ul> <li><a href="sql-select.php">SQL-Befehle</a>: Verwendung von SQL-Anweisungen zum Speichern, Abrufen und Bearbeiten von Daten in einer relationalen Datenbank. </li> <li><a href="sql-create-table.php">Tabellenbearbeitung</a>: Verwendung von SQL-Anweisungen zum Verwalten von Tabellen in der Datenbank. </li> <li><a href="sql-syntax.php">SQL-Syntax</a>: Eine einzelne Seite mit der Syntax für alle SQL-Befehle in diesem Tutorial. </li> </ul> <p>Für jeden Befehl wird zunächst die SQL-Syntax vorgestellt und erläutert und dann ein Beispiel gegeben. Am Ende des Tutorials sind Sie mit den allgemeinen Grundlagen der SQL-Syntax vertraut. Sie werden auch in der Lage sein, SQL-Abfragen mit der korrekten Syntax zu schreiben. Meiner Erfahrung nach ist es viel einfacher, die Grundlagen von SQL zu verstehen als alle Varianten dieser Datenbanksprache zu beherrschen, und ich hoffe, dass Sie zum gleichen Schluss kommen.</p> <p>Genug der einleitenden Worte. Setzen Sie einen Bookmark auf diese Seite, und <a href="sql-select.php">lernen Sie SQL</a>!</p> <p><i>Hinweis</i>: Als Leiter eines SQL- oder Datenbankkurses können Sie diese Seite gerne als Referenzmaterial für Ihre Kursteilnehmer verwenden. <p><center>Diese Seite wurde zuletzt am 26.06.2022 aktualisiert</center> <br> <center>  <div id='div-gpt-ad-1602455281449-0' class="ad-footer"> <script> googletag.cmd.push(function() { googletag.display('div-gpt-ad-1602455281449-0'); }); </script> </div> <br><br> <hr> <p>Copyright © 2024   <a href="https://www.1keydata.com/">1keydata.com</a>   Alle Rechte vorbehalten</p> </center></td></tr></table> </div> </div> <div id="col1"> <br><br> <div id="left-nav" class="mousescroll"> <ul> <br><br> <li><a href="sql-select.php">SQL SELECT</a></li> <li><a href="distinct.php">SQL DISTINCT</a></li> <li><a href="sql-where.php">SQL WHERE</a></li> <li><a href="sql-and-or.php">SQL AND OR</a></li> <li><a href="sql-in.php">SQL IN</a></li> <li><a href="sql-between.php">SQL BETWEEN</a></li> <li><a href="sql-like.php">SQL LIKE</a></li> <li><a href="sql-order-by.php">SQL ORDER BY</a></li> <li><a href="sql-funktionen.php">SQL Funktionen</a></li> <li><a href="sql-count.php">SQL COUNT</a></li> <li><a href="sql-group-by.php">SQL GROUP BY</a></li> <li><a href="sql-having.php">SQL HAVING</a></li> <li><a href="sql-alias.php">SQL ALIAS</a></li> <li><a href="sql-join.php">SQL JOIN</a></li> <li><a href="sql-outer-join.php">SQL OUTER JOIN</a></li> <li><a href="sql-unterabfrage.php">SQL Unterabfrage</a></li> <li><a href="sql-with.php">SQL WITH</a></li> <li><a href="sql-exists.php">SQL EXISTS</a></li> <li><a href="sql-union.php">SQL UNION</a></li> <li><a href="sql-union-all.php">SQL UNION ALL</a></li> <li><a href="inline-ansicht.php">SQL Inline-Ansicht</a></li> <li><a href="sql-intersect.php">SQL INTERSECT</a></li> <li><a href="sql-minus.php">SQL MINUS</a></li> <li><a href="sequence-nextval.php">SEQUENCE und NEXTVAL</a></li> <li><a href="sql-kaskadieren.php">SQL Kaskadieren</a></li> <li><a href="sql-substring.php">SQL SUBSTRING</a></li> <li><a href="sql-trim.php">SQL TRIM</a></li> <li>   </li> <li><a href="sql-create-table.php">SQL CREATE TABLE</a></li> <li><a href="sql-create-view.php">SQL CREATE VIEW</a></li> <li><a href="sql-create-index.php">SQL CREATE INDEX</a></li> <li><a href="sql-alter-table.php">SQL ALTER TABLE</a></li> <li><a href="sql-primaerschluessels.php">SQL Primärschlüssels</a></li> <li><a href="sql-fremdschluessels.php">SQL Fremdschlüssels</a></li> <li><a href="sql-drop-table.php">SQL DROP TABLE</a></li> <li><a href="sql-truncate-table.php">SQL TRUNCATE TABLE</a></li> <li><a href="sql-use.php">SQL USE</a></li> <li><a href="sql-insert-into.php">SQL INSERT INTO</a></li> <li><a href="sql-update.php">SQL UPDATE</a></li> <li><a href="sql-delete.php">SQL DELETE FROM</a></li> <li>   </li> <li><a href="sql-seitenuebersicht.php">Seitenübersicht</a></li> <br><br><br><br><br><br> </ul></div> </div> <div id="col3"> <br><br><center>  <ins class="adsbygoogle rslot" style="display:block" data-ad-client="ca-pub-4254904157393454" data-ad-slot="3897695228" data-ad-format="auto"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </center> </div></center> <div id="custom-search">  <form id="searchbox_014264424332737199420:aef0rmq1bqs" action="https://www.1keydata.com/de/sql/result.php"> <input type="hidden" name="cx" value="014264424332737199420:aef0rmq1bqs" /> <input name="q" type="text" size="17" /> <input type="submit" name="sa" value="Suchen" /> <input type="hidden" name="cof" value="FORID:10" /> </form> <script defer type="text/javascript" src="https://www.google.com/coop/cse/brand?form=searchbox_014264424332737199420%3Aaef0rmq1bqs"></script>  </div>  <script async src="https://www.googletagmanager.com/gtag/js?id=UA-484268-2"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-484268-2'); </script> </body> </html>