InterBase Referential Integrity

InterBase has a number of options for Referential Integrity that are powerful to use and simplify keeping data valid.

This video covers (more reading from the InterBase DocWiki on the links here)

• Primary Key
• Unique Key
• Foreign Key
• Check Constraints

Tip for adding Constraints.

One very cool tip in the video is to use constraints to add in a unique key, this way you can drop it easily at runtime.  Remember, the field needs to be marketed NOT NULL to enable a primary or unique key.

ALTER TABLE CUSTOMER ADD CONSTRAINT U_TEST UNIQUE (CUSTOMER_NAME);

The above example names the constraint U_TEST. (you can put whatever value you want in to name it, making it easy to drop with the following statement.

ALTER TABLE CUSTOMER DROP CONSTRAINT U_TEST;

InterBase Labs

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