To remove a relation from an SQL database, we use the ______ command.
Purge
Explanation: Drop table deletes the whole structure of the relation .purge removes the table which cannot be obtained again.
Delete
Remove
Drop table
Category: Computer Science
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.
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.
3, 20
Explanation: Varchar changes its length accordingly whereas char has a specific length which has to be filled by either letters or spaces.
20, 4
20, 20
3, 4
The basic data type char(n) is a _____ length character string and varchar(n) is _____ length character.
The basic data type char(n) is a _____ length character string and varchar(n) is _____ length character.
Fixed, variable
Explanation: Varchar changes its length accordingly whereas char has a specific length which has to be filled by either letters or spaces.
Variable, equal
Equal, variable
Fixed, equal
SELECT * FROM employee What type of statement is this?
SELECT * FROM employee What type of statement is this?
DML
Explanation: Select operation just shows the required fields of the relation. So it forms a DML.
DDL
View
Integrity constraint
CREATE TABLE employee (name VARCHAR, id INTEGER) What type of statement is this?
CREATE TABLE employee (name VARCHAR, id INTEGER) What type of statement is this?
DDL
Explanation: Data Definition language is the language which performs all the operation in defining structure of relation.
DML
View
Integrity constraint
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?
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?
DML(Data Manipulation Langauge)
Explanation: DML performs the change in the values of the relation.
DDL(Data Definition Langauge)
Relational Schema
Query
Which one of the following is used to define the structure of the relation, deleting relations and relating schemas?
Which one of the following is used to define the structure of the relation, deleting relations and relating schemas?
DDL(Data Definition Langauge)
Explanation: Data Definition language is the language which performs all the operation in defining structure of relation.
DML(Data Manipulation Langauge)
Query
Relational Schema
The _________ provides a set of operations that take one or more relations as input and return a relation as an output.
The _________ provides a set of operations that take one or more relations as input and return a relation as an output.
Relational algebra
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Scheme diagram
Relation flow
Schematic representation
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.
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.
Schema diagram
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Relational algebra
Database diagram
Schema flow
The _______ operator takes the results of two queries and returns only rows that appear in both result sets.
The _______ operator takes the results of two queries and returns only rows that appear in both result sets.
Intersect
WellDone! Your Selected answer is Correct. The union operator gives the result which is the union of two queries and difference is the one where query which is not a part of second query
Projection
Difference
Union