SQL PRIMARY KEY

In SQL, a primary key is a unique identifier that is used to identify each row of data in a table. It is a column or a set of columns that has a unique value for each row in the table, and is used to enforce data integrity and ensure that there are no any duplicate records in the table. If you want to generate a primary key, you should include a PRIMARY KEY constraint when you create or change a table. A primary key can be created in SQL when a...

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