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u |
Different
tables are related to one another with
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primary
and foreign key matches.
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n |
Ex.
Sales order table holds customer FK
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u |
Relationships
may be:
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n |
(Zero
or) One-to-one
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n |
(Zero
or) One-to-Many
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n |
Self-join
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u |
Relational
Integrity (RI) can be enforced with
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triggers,
RI Builder, or code
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n |
Ex.
Cannot delete invoice with detail items
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