SQL 1: Difference between primary key and unique key 2: Why we use Normalisation and there different types 3: Some questions from SQL query, Join, delete, update, etc.

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Answers to SQL related questions for Software Engineer interview

Primary key uniquely identifies a record in a table, while unique key ensures that no two records have the same value for a specific column
Normalization is used to eliminate data redundancy and improve data integrity. Types include 1NF, 2NF, 3NF, BCNF, 4NF, 5NF
SQL queries can be used to retrieve data from one or more tables using joins. Delete and update statements can be used to modify data in a table

SQL 1: Difference between primary key and unique key 2: Why we use Normalisation and there different types 3: Some questions from SQL query, Join, delete, update, etc.

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