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8. How many results will the following query give on a table set up like the Food table, when the id is the primary key?
Posted: Sun Jul 10, 2022 11:23 am
by answerhappygod
- 8 How Many Results Will The Following Query Give On A Table Set Up Like The Food Table When The Id Is The Primary Key 1 (30.11 KiB) Viewed 57 times
8. How many results will the following query give on a table set up like the Food table, when the id is the primary key? Why? 1 SELECT FROM Food WHERE id=123; 0 or 1. It can't be more, because id is the primary key, and so unique. Exactly 1. It can't be more, because id is the primary key, and so unique. It can't be zero because a primary key can't be NULL. O 123. The id is a counter, so there must have been that many when it was set. We can't know without seeing the data. Incorrect It can't be NULL, that is undefined when a record exists, but there may be no record with that id.