DATABASE FUNDAMENTALS
WHAT IS DATABASE MANAGEMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Foreign Key
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Primary Key
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Entity integrity
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Referential integrity
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Detailed explanation-1: -Referential integrity requires that a foreign key must have a matching primary key or it must be null. This constraint is specified between two tables (parent and child); it maintains the correspondence between rows in these tables. It means the reference from a row in one table to another table must be valid.
Detailed explanation-2: -Referential Integrity Constraint ensures that there must always exist a valid relationship between two relational database tables. This valid relationship between the two tables confirms that a foreign key exists in a table.
Detailed explanation-3: -This relational data model therefore enforces a constraint called referential integrity, which states that every nonnull foreign key value must match an existing primary key value.
Detailed explanation-4: -FOREIGN KEY Constraint The relationship between the child and the parent tables is maintained by checking the existence of the child table FOREIGN KEY values in the referenced parent table’s PRIMARY KEY before inserting these values into the child table.