BSc IT - Database Management System

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Explain various domain constraints and unique constraints used in SQL.

In SQL, domain constraints and unique constraints are used to make sure that the data stored in a database is accurate and follows specific rules.

A domain constraint makes sure that the value stored in a column is of the correct type or within a
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Explain syntax and use of DDL ststements.

DDL stands for Data Definition Language.

These are SQL commands used to define or change the structure of a database. They help you create, modify, or delete database objects like tables, indexes, and schemas.

## Common DDL Commands with Syntax and Use

CREATE
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Explain use of IN, BETWEEN operators with example.

In SQL, the IN operator is used to check if a value matches any value in a list. It makes it easy to write multiple `OR` conditions in a short way. For example, if you want to find students from India, USA, or UK, you can write:

SELECT * FROM Students WHERE Country IN
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Explain Generalization and Specialization.

In a DBMS , Generalization is the process of combining multiple specific entities into a more general, common entity based on shared attributes. For example, if you have entities like Car, Bike, and Truck, you can generalize them into a common entity called Vehicle that holds
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Explain level of abstraction of Database.

In a DBMS , there are three levels of data abstraction that help users see and understand data in different ways:

Physical Level : This is the lowest level. It tells how data is actually stored on the storage devices, like files, indexes, or structures.
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Define Primary key and Foreign key.

Primary Key is a column (or a combination of columns) that uniquely identifies each row in a table. It must have unique values and cannot contain nulls. For example, in a Students
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Difference between strong entity and weak entity.

In a DBMS , a strong entity is an entity that can be uniquely identified by its own attributes without depending on any other entity. It has a primary key and can exist independently in the database. For example, a Student entity with a unique StudentID is a strong entity because it
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What is Data and Information.

In a DBMS (Database Management System) , data refers to the raw values, facts, or figures stored in tables, like names, IDs, numbers, or dates. It is the basic building block and doesn’t have much meaning by itself. On the other hand, information is the result of processing and
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