Database Management System MCQs
749+ questions with answers
A relational database consists of a collection of
A ________ in a table represents a relationship among a set of values.
The term _______ is used to refer to a row.
The term attribute refers to a ___________ of a table.
For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.
Database __________ which is the logical design of the database, and the database _______ which is a snapshot of the data in the database at a given instant in time.
Department (dept name, building, budget) and Employee (employee_id, name, dept name, salary) Here the dept_name attribute appears in both the relations. Here using common attributes in relation schema is one way of relating ___________ relations.
A domain is atomic if elements of the domain are considered to be ____________ units.
The tuples of the relations can be of ________ order.
Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?
Consider attributes ID, CITY and NAME. Which one of this can be considered as a super key?
The subset of a super key is a candidate key under what condition?
A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.
Which one of the following attribute can be taken as a primary key?
Which one of the following cannot be taken as a primary key?
The relation with the attribute which is the primary key is referenced in another relation. The relation which has the attribute as a primary key is called ______________
The ______ is the one in which the primary key of one relation is used as a normal attribute in another relation.
A _________ integrity constraint requires that the values appearing in specified attributes of any tuple in the referencing relation also appear in specified attributes of at least one tuple in the referenced relation.
Using which language can a user request information from a database?
Student(ID, name, dept name, tot_cred) In this query which attributes form the primary key?
Which one of the following is a procedural language?
The_____ operation allows the combining of two relations by merging pairs of tuples, one from each relation, into a single tuple.
The result which operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.
The _______operation performs a set union of two “similarly structured” tables
The _______ operator takes the results of two queries and returns only rows that appear in both result sets.
A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.
The _________ provides a set of operations that take one or more relations as input and return a relation as an output.
Which one of the following is used to define the structure of the relation, deleting relations and relating schemas?
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?
The basic data type char(n) is a _____ length character string and varchar(n) is _____ length character.
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.
Updates that violate __________ are disallowed.
The ______ clause allows us to select only those rows in the result relation of the ____ clause that satisfy a specified predicate.
The query given below will not give an error. Which one of the following has to be replaced to get the desired output? SELECT ID, name, dept name, salary * 1.1 WHERE instructor;
The ________ clause is used to list the attributes desired in the result of a query.
This Query can be replaced by which one of the following? SELECT name, course_id FROM instructor, teaches WHERE instructor_ID= teaches_ID;
Which of the following statements contains an error?
In the given query which of the keyword has to be inserted? INSERT INTO employee _____ (1002,Joey,2000);
’_ _ _ ’ matches any string of ______ three characters. ’_ _ _ %’ matches any string of at ______ three characters.
In SQL the spaces at the end of the string are removed by _______ function.
The intersection operator is used to get the _____ tuples.
The union operation automatically __________ unlike the select clause.
If we want to retain all duplicates, we must write ________ in place of union.
The number of attributes in relation is called as its
_____ clause is an additional filter that is applied to the result.
_________ joins are SQL server default
The _____________ is essentially used to search for patterns in target string.
A _____ indicates an absent value that may exist but be unknown or that may not exist at all.
If the attribute phone number is included in the relation all the values need not be entered into the phone number column. This type of entry is given as