Should we update primary key?

Should we update primary key?

While there is nothing that will prevent you from updating a primary key (except integrity constraint), it may not be a good idea: From a performance point of view: You will need to update all foreign keys that reference the updated key. A single update can lead to the update of potentially lots of tables/rows.

How do you update a primary key?

Updating a primary key

1. Repeat the row containing the original primary key value you want to change.
2. Change the primary key in the new row to the required value.
3. Use the SAVE primary command to verify that there are no other Db2 errors.
4. Delete the original row.

What should the primary key be?

Primary keys should be immutable, that is, never changed or re-used; they should be deleted along with the associated record. Primary keys should be anonymous integer or numeric identifiers.

What’s the best practice for primary keys in tables?

Primary keys should be as small as necessary. Prefer a numeric type because numeric types are stored in a much more compact format than character formats. This is because most primary keys will be foreign keys in another table as well as used in multiple indexes.

What happens when you update the PK in a primary table?

When you then update a value in the PK column in your primary table, the FK references in the other tables will be updated to point at the new value, preserving data integrity. When you find it necessary to update a primary key value as well as all matching foreign keys, then the entire design needs to be fixed.

Is it best to never update primary key?

It is a best practice to never update the primary key, and if you find it necessary, you should use a Surrogate Primary Key, which is a key not derived from application data. As a result its value is unrelated to the business logic and never needs to change (and should be invisible to the end user).

How to update primary key Stack Overflow SQL Server?

Note that the high-end vendors do not allow “cascade update”. First INSERT-SELECT a new row in the parent table, from the old row, with the new Key or RID value Second, for all child tables, working top to bottom, INSERT-SELECT the new rows, from the old rows, with the new Key or RID value