Which type of key can enforce rules such as cascading updates or deletions?

Question

BlackTom AI · Accepted Answer

To tackle this question, I will evaluate what each type of key does in a relational database context.
Option 1: 'A primary key.' A primary key uniquely identifies each row within a table, but by itself it does not enforce cascading updates or deletions across related tables. The cascade behavior is defined on foreign key constraints, not on primary keys.
Option 2: 'A foreign key.' This is the correct concept for cascade rules. A foreign key enforces referential integrity by linking to a primary (or candidate) key in another table, and it can specify actions like ON UPDATE CASCADE and ON DELETE CASCADE to propagate changes or deletions across related rows.
Option 3: 'A partial key.' The term 'partial key' is not a standard, widely used key type in relational databases. It does not convey the mechanism for cascading actions, so it would be misleading here.
Option 4: 'A surrogate key.' A surrogate key is an artificial identifier, such as an auto-incremented number. While it can be used as a foreign key reference, the surrogate key itself does not inherently provide cascade behavior; cascading is a property of the foreign key constraint, not the surrogate key type.
In summary, only the foreign key structure directly supports and configures cascading updates or deletions through its constraint options, whereas the other key types serve different primary purposes within table design.

Which type of key can enforce rules such as cascading updates or deletions?

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