Question

what is primary key?why is it necessary to have primary key in table​ ​

Answer 1

Answer:

here is your ans

Explanation:

Each database table needs a primary key because it ensures row-level accessibility. ... The values that compose a primary key column are unique; no two values are the same. Each table has one and only one primary key, which can consist of one or many columns. A concatenated primary key comprises two or more columns.

Answer 2

Answer:

Each database table needs a primary keybecause it ensures row-level accessibility. If you choose an appropriate primary key, you can specify a primary key value, which lets you query each table row individually and modify each row without altering other rows in the same table.

Explanation:

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