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web.groovymark@gmail.com
- November 7, 2024
Question 21
Which SQL statement is used to create a new view based on a SELECT query?
a) CREATE VIEW
b) NEW VIEW
c) ADD VIEW
d) DEFINE VIEW
Correct Answer: a) CREATE VIEW
Explanation: The CREATE VIEW statement defines a new view based on a SELECT query, simplifying data retrieval.
Question 22
Which SQL operator is used to test for a NULL value?
a) IS NULL
b) NULL TEST
c) IS EMPTY
d) NOT NULL
Correct Answer: a) IS NULL
Explanation: The IS NULL operator is used to test whether a value is NULL in SQL.
Question 23
What does the term ‘join’ refer to in SQL?
a) Combining data from two or more tables
b) Removing duplicates from a table
c) Sorting records in a table
d) Creating a new database
Correct Answer: a) Combining data from two or more tables
Explanation: A join in SQL combines data from two or more tables based on a related column between them.
Question 24
Which SQL function is used to return the length of a string?
a) LENGTH()
b) SIZE()
c) COUNT()
d) CHAR_LENGTH()
Correct Answer: a) LENGTH()
Explanation: The LENGTH() function returns the number of characters in a string in SQL.
Question 25
Which SQL clause is used to specify the number of rows to be returned?
a) LIMIT
b) TOP
c) RANK
d) COUNT
Correct Answer: a) LIMIT
Explanation: The LIMIT clause is used to restrict the number of rows returned by a SQL query.
Question 26
Which SQL statement is used to create a new database?
a) NEW DATABASE
b) CREATE DATABASE
c) ADD DATABASE
d) DEFINE DATABASE
Correct Answer: b) CREATE DATABASE
Explanation: The CREATE DATABASE statement is used to define a new database within the database management system.
Question 27
Which SQL keyword is used to specify an alternative value if a NULL value is encountered?
a) IFNULL
b) COALESCE
c) NULLIF
d) DEFAULT
Correct Answer: b) COALESCE
Explanation: The COALESCE function returns the first non-NULL value in a list, allowing for default values in the presence of NULLs.
Question 28
What does the term ‘schema’ refer to in a database?
a) The physical storage of data
b) The overall structure of the database
c) The data types of columns
d) The user privileges
Correct Answer: b) The overall structure of the database
Explanation: A schema defines the structure of a database, including tables, columns, data types, and relationships.
Question 29
Which SQL command is used to grant a user read-only access to a table?
a) GRANT SELECT
b) GRANT READ
c) GRANT ALL
d) GRANT WRITE
Correct Answer: a) GRANT SELECT
Explanation: The GRANT SELECT command is used to provide a user with permission to read data from a specific table without allowing modifications.
Question 30
Which SQL keyword is used to specify the data type of a column in a table?
a) TYPE
b) DATA TYPE
c) COLUMN TYPE
d) DATA
Correct Answer: b) DATA TYPE
Explanation: The DATA TYPE specifies the type of data that can be stored in a column, such as INTEGER, VARCHAR, DATE, etc.
Question 31
Which SQL command is used to create a new table with specified columns and data types?
a) CREATE TABLE
b) ADD TABLE
c) NEW TABLE
d) DEFINE TABLE
Correct Answer: a) CREATE TABLE
Explanation: The CREATE TABLE command is used to define a new table and its columns within the database.
Question 32
Which SQL statement is used to modify the values of a specific column in existing records?
a) UPDATE
b) CHANGE
c) MODIFY
d) ALTER
Correct Answer: a) UPDATE
Explanation: The UPDATE statement is used to change the values of one or more columns in existing records based on specified conditions.
Question 33
Which SQL function is used to remove leading and trailing spaces from a string?
a) TRIM()
b) CLEAN()
c) STRIP()
d) REMOVE()
Correct Answer: a) TRIM()
Explanation: The TRIM() function removes leading and trailing whitespace from a string in SQL.
Question 34
What is the purpose of the HAVING clause in SQL?
a) To filter records before grouping
b) To sort the result set
c) To filter records after grouping
d) To join multiple tables
Correct Answer: c) To filter records after grouping
Explanation: The HAVING clause is used to filter results after aggregation has taken place, allowing conditions on grouped data.
Question 35
Which SQL statement is used to remove a row from a table?
a) DROP
b) REMOVE
c) DELETE
d) TRUNCATE
Correct Answer: c) DELETE
Explanation: The DELETE statement is used to remove specific rows from a table based on defined conditions.
Question 36
What does the SQL function LCASE() do?
a) Converts a string to uppercase
b) Removes spaces from a string
c) Converts a string to lowercase
d) Counts characters in a string
Correct Answer: c) Converts a string to lowercase
Explanation: The LCASE() function converts all uppercase characters in a string to lowercase.
Question 37
Which SQL operator is used to compare two values for equality?
a) =
b) <>
c) !=
d) IS
Correct Answer: a) =
Explanation: The equal sign (=) is the operator used to compare two values for equality in SQL.
Question 38
Which SQL command is used to remove a column from a table?
a) DROP COLUMN
b) REMOVE COLUMN
c) DELETE COLUMN
d) ALTER COLUMN
Correct Answer: a) DROP COLUMN
Explanation: The DROP COLUMN statement is used to remove a specified column from an existing table.
Question 39
What is the purpose of a data dictionary in a database?
a) To store user data
b) To define user permissions
c) To describe database structure and objects
d) To keep track of transactions
Correct Answer: c) To describe database structure and objects
Explanation: A data dictionary contains metadata about the database structure, including details about tables, columns, indexes, and constraints.
Question 40
Which SQL command is used to create a new user in the database?
a) CREATE USER
b) ADD USER
c) NEW USER
d) DEFINE USER
Correct Answer: a) CREATE USER
Explanation: The CREATE USER command establishes a new user account in the database management system.
