Hitachi System Engineer Interview Questions, Process, and Tips for Experienced

Normalization in SQL is the process of organizing data in a database to reduce redundancy and improve data integrity. A cursor in SQL is a database object used to retrieve and manipulate data row by row.

• Normalization in SQL involves breaking down a large table into smaller tables and defining relationships between them to reduce redundancy.

• Cursors in SQL are used to fetch and process individual rows returned by a query...read more

Abstract classes can have both abstract and non-abstract methods, while interfaces can only have abstract methods.

• Abstract classes can have constructors, fields, and non-abstract methods along with abstract methods

• Interfaces can only have abstract methods and constants

• A class can implement multiple interfaces but can only inherit from one abstract class

Const keyword is used to declare constants at compile time, while read-only keyword is used to create immutable fields that can only be assigned a value at runtime.

• Const values are determined at compile time and cannot be changed, while read-only values can only be assigned a value once at runtime.

• Const fields are implicitly static, while read-only fields are not.

• Example: const int x = 5; read-only int y = 10;

Sample query to join tables using SQL

• Use the JOIN keyword to combine rows from two or more tables based on a related column between them

• Specify the columns to be selected from each table

• Use the ON keyword to specify the join condition