Database Questions and Answers – SQL Basics and SQL Data Definition

This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “SQL Basics and SQL Data Definition”.

1. Which one of the following is used to define the structure of the relation, deleting relations and relating schemas?
a) DML(Data Manipulation Langauge)
b) DDL(Data Definition Langauge)
c) Query
d) Relational Schema
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2. Which one of the following provides the ability to query information from the database and to insert tuples into, delete tuples from, and modify tuples in the database?
a) DML(Data Manipulation Langauge)
b) DDL(Data Definition Langauge)
c) Query
d) Relational Schema
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3.

CREATE TABLE employee (name VARCHAR, id INTEGER)

What type of statement is this?
a) DML
b) DDL
c) View
d) Integrity constraint
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4.

SELECT * FROM employee

What type of statement is this?
a) DML
b) DDL
c) View
d) Integrity constraint
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5. The basic data type char(n) is a _____ length character string and varchar(n) is _____ length character.
a) Fixed, equal
b) Equal, variable
c) Fixed, variable
d) Variable, equal
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6. An attribute A of datatype varchar(20) has the value “Avi”. The attribute B of datatype char(20) has value ”Reed”. Here attribute A has ____ spaces and attribute B has ____ spaces.
a) 3, 20
b) 20, 4
c) 20, 20
d) 3, 4
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7. To remove a relation from an SQL database, we use the ______ command.
a) Delete
b) Purge
c) Remove
d) Drop table
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8.

DELETE FROM r;   //r - relation

This command performs which of the following action?
a) Remove relation
b) Clear relation entries
c) Delete fields
d) Delete rows
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9.

INSERT INTO instructor VALUES (10211, ’Smith’, ’Biology’, 66000);

What type of statement is this?
a) Query
b) DML
c) Relational
d) DDL
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10. Updates that violate __________ are disallowed.
a) Integrity constraints
b) Transaction control
c) Authorization
d) DDL constraints
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Sanfoundry Global Education & Learning Series – Database Management System.