Was bedeutet der folgende Ausdruck:
ON DELETE SET NULL / ON UPDATE SET NULL
ON DELETE SET NULL / ON UPDATE SET NULL
Wenn in der Master-Tabelle ein Wert gelöscht/verändert wird, werden die Referenzen in der Detail-Tabelle auf NULL gesetzt
Tags: Datenbank, detail-tabelle, master-tabelle, NULL, ON DELETE SET NULL, ON UPDATE SET NULL, referenz, sql
Source:
Source:
Flashcard set info:
Author: Stejan
Main topic: Informatik
Topic: SQL
School / Univ.: ZbW
City: St. Gallen
Published: 04.03.2011
Tags: sql database datenbank
Card tags:
All cards (26)
ALL (1)
AUTO_INCREMENT (1)
bedingung (1)
befehl (1)
case sensitive (1)
CHAR (1)
column (1)
Constraint (1)
constraints (1)
create (3)
CREATE (2)
data dictionary (2)
database (1)
datenbank (2)
Datenbank (24)
datenbasis (2)
datentyp (1)
dbms (1)
dbs (1)
ddl (3)
definition (2)
DELETE (1)
DESC (1)
detail-tabelle (2)
DISTINCT (1)
dml (2)
dql (2)
FOREIGN KEY (1)
FROM (1)
INSERT (2)
join (1)
like (1)
master-tabelle (2)
mysql (1)
NULL (1)
ON UPDATE SET NULL (1)
ORDER BY (1)
Primärschlüssel (1)
PRIMARY KEY (3)
referenz (1)
schema (1)
SELECT (3)
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sql (18)
SQL (3)
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TABLE (1)
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