2. What is Primary Key, Foreign Key [SQL], Normalization in SQL and why it is required.

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Accepted Answer

Primary Key, Foreign Key and Normalization are important concepts in SQL for data integrity and efficient data retrieval.

Primary Key is a unique identifier for each record in a table.
Foreign Key is a field in one table that refers to the Primary Key in another table.
Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.
Normalization helps to avoid data inconsistencies and anomalies.
Example: A customer table may have a Primary Key of customer_id, and an orders table may have a Foreign Key of customer_id to link the two tables.
Normalization can be achieved through various forms such as 1NF, 2NF, 3NF, etc.

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