Nippon Data Systems Application Software Engineer 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 procedure is a precompiled SQL code that can be reused and executed multiple times.

• Stored procedures are used to improve performance and security of database operations.

• They can accept input parameters and return output parameters or result sets.

• Stored procedures can be called from within other SQL statements or from application code.

• Examples of stored procedures include inserting data into a table, updating rec...read more