Maas Infosolutions Interview Questions and Answers

A view in SQL server is a virtual table that contains the result set of a SELECT statement.

• Views are used to simplify complex queries by storing them as a virtual table.

• Views can be used to restrict access to specific columns or rows of a table.

• Views can improve performance by pre-computing expensive queries.

• Example: CREATE VIEW vwEmployee AS SELECT FirstName, LastName FROM Employees;

Transactions in SQL server ensure data integrity by grouping multiple SQL statements into a single unit of work.

• Transactions help maintain data consistency by either committing all changes or rolling them back if an error occurs.

• Use BEGIN TRANSACTION to start a transaction, COMMIT to save changes, and ROLLBACK to undo changes.

• Example: BEGIN TRANSACTION; UPDATE table SET column = value; COMMIT; - commits the changes mad...read more

Encapsulation is the concept of bundling data and methods that operate on the data into a single unit.

• Encapsulation helps in hiding the internal state of an object and only exposing necessary functionalities.

• It allows for better control over the data by preventing direct access from outside the class.

• Encapsulation promotes code reusability and modularity by keeping related data and methods together.

• Example: In a class ...read more

Roll back in SQL server is a process of reverting the database to a previous state before a transaction was executed.

• Roll back is used to undo changes made by a transaction that has not been committed.

• It can be done using the ROLLBACK statement in SQL.

• Rolling back a transaction restores the data to its original state before the transaction started.

• Example: ROLLBACK TRANSACTION;

• Roll back is important for maintaining dat...read more