Basics Of DBMS

DBMS is database management system. Tables, tuples, keys are used to maintain the data. It is important that you know the shortcuts and tricks so that you can solve these questions quickly because time is the most important factor. These tricks can help you solve questions in bank exams, government exams, and many other exams that have a time limit. To know more about Basics of DBMS  and sql explore the article further!

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DBMS

DBMS is database management system. Databases are the collection of data in order to store and retrieve data. The database consists of data which can be a numeric, alphabetic and also alphanumeric form. Analyzing data is a key feature of database management system that is DBMS.  DBMS allows the definition, creation, querying, update, and administration of databases. Language supported and widely used for querying and accessing the database is SQL.

Source: Quora.com

Solved Questions

Q1. Which type of database management system is MySQL?

a) Object-oriented
b) Hierarchical
c) Relational
d) Network

Answer: Relational. MySQL is a ‘relational’ DBMS. It is efficient at relating data in two different tables and joining information from them. Hierarchical and Network DBMS are based on parent-child relationships of records. Object-oriented DBMS use objects to represent models. Therefore relational is the answer.

Q2.Create table employee (name varchar, id integer)

What type of statement is this?
a) DML
b) DDL
c) View
d) Integrity constraint

Answer: DDL, Data Definition language is the language which performs all the operation in defining the structure of relation.

Q3.  Large collection of files are called ____________

Browse more Topics under Dbms

• Types of DBMS
• Function & Purpose of DBMS
• Database Management System Practice Questions

Common Terminologies

Some of the common terminologies of DBMS are

1. Tuple: The rows in the database are often known as tuples.
2. Table: Table is a collection of tuples and related information along with a key to distinguish the data. Although a table can have duplication of data tuples.
3. Schema: Schema is the structure of the relation or a table.
4. Data redundancy: Data redundancy ensures there are no multiple occurrences of same data hence avoids data duplication.
5. Keys:  Keys in a table are used to identify the unique attribute of the table.

Q1. What is data in a MySQL database organized into?

a) Objects
b) Tables
c) Networks
d) Filesystems

Answer: Tables, Since MySQL is an RDBMS, it’s data is organized into tables for establishing relationships. A table is a collection of rows and columns, where each row is a record and columns describe the feature of records. Therefore tables are the answer.

SQL Query Language

In DBMS the SQL query language has DML, DDL, DCL, and TCL.

• DML is data manipulation language and is used for selecting, retrieving, storing, modifying, deleting, inserting and updating entries in the database. SELECT, UPDATE, INSERT, DELETE are some of the DML query statements

eg: SELECT *;  this statement will select all the values and tuple from the database and display them as an output of this query

• DDL is data definition language and is useful for defining the schema and structure of the database. Commands like DROP, CREATE, ALTER, TRUNCATE, COMMENT, and RENAME are used.

eg: DROP *table name*; this statement will delete the values as well as the structure of the database.

• DCL is data control language and is useful for granting and revoking rights to and from a user. The command like GRANT and REVOKE are used.

• TCL is transaction control language and is useful for managing the transaction in the database. Commands like COMMIT, ROLLBACK, SAVEPOINT and SET TRANSACTION are used.

Q1. _________commands in SQL allow controlling access to data within database.
a) Database
b) Data
c) Data control
d) All of the Mentioned

Answer: Data Control. Data control is used for the controlling the access to the database. Therefore data control is the answer.

Q2. Which of the following is not included in DML (Data Manipulation Language)
a) INSERT
b) UPDATE
c) DELETE
d) CREATE

Answer: CREATE. The CREATE TABLE statement is used to create a table in a database. Tables are organized into rows and columns, and each table must have a name. Therefore CREATE is the answer.

Practice Questions

Q1.In SQL, which of the following is not a data Manipulation Language Commands?
a) Delete
b) Truncate
c) Update
d) Create

Answer: Truncate

Q2. In SQL, which command(s) is(are) used to change a table’s storage characteristics?
a) ALTER TABLE
b) MODIFY TABLE
c) CHANGE TABLE
d) All of the Mentioned
Answer: ALTER TABLE

Q3. What represents a ‘tuple’ in a relational database?
a) Table
b) Row
c) Column
d) Object

Answer: Row

Q4.  The transaction completes its execution is said to be
a) Committed
b) Aborted
c) Rolled back
d) Failed

Answer: Committed