Senior Data Associate Interview Questions and Answers

Primary key uniquely identifies a record in a table, while unique key ensures that all values in a column are distinct.

• Primary key can't have null values, while unique key can have one null value.

• A table can have only one primary key, but multiple unique keys.

• Primary key is used as a foreign key in other tables, while unique key is not.

• Example: Employee ID can be a primary key, while email address can be a unique key.

Stored procedures are pre-written SQL codes that can be saved and reused multiple times.

• Stored procedures are used to simplify complex queries and reduce network traffic.

• They can be used to perform multiple operations in a single transaction.

• They can be parameterized to accept input values and return output values.

• They can be used to enforce business rules and security measures.

• Examples include creating a new user, updating inventory, and generating reports.