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Last active July 5, 2018 00:26
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sql.md

  1. TODO

    • Kreuztabelle, Kartesisches Produkt, cross join
    • The LEFT JOIN keyword returns all records from the left table (table1), and the matched records from the right table (table2). The result is NULL from the right side, if there is no match. The RIGHT JOIN keyword returns all records from the right table (table2), and the matched records from the left table (table1). The result is NULL from the left side, when there is no match.
    • The INNER JOIN keyword selects records that have matching values in both tables.
    • Es folgt ein Fehler (insofern keine Kaskadierung deklariert ist), weil abhängige Datensätze bestehen.
    • Prozedur, keine Argumente, Patten matching (alle PLZ, die mit 08 beginnen).
Ausgabe A B C
Alle Kunden
Nur besuchte Kunden x x
Alle Besuchstermine x
Nur an Kunden zugewiesene Besuchstermine x x
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