Explore topic-wise MCQs in Structured Query Language (SQL).

This section includes 81 Mcqs, each offering curated multiple-choice questions to sharpen your Structured Query Language (SQL) knowledge and support exam preparation. Choose a topic below to get started.

1.

NULL is%!

A. the same as 0 for integer
B. the same as blank for character
C. the same as 0 for integer and blank for character
D. not a value
Answer» E.
2.

Which of the following is a valid SQL type?%!

A. CHARACTER
B. NUMERIC
C. FLOAT
D. All of the above
Answer» E.
3.

Count function in SQL returns the number of%!

A. values.
B. distinct values.
C. groups.
D. columns.
Answer» B. distinct values.
4.

'AS' clause is used in SQL for%!

A. Selection operation.
B. Rename operation.
C. Join operation.
D. Projection operation.
Answer» C. Join operation.
5.

Find the names of these cities with temperature and condition whose condition is neither sunny nor cloudy%!

A. SELECT city, temperature, condition FROM weather WHERE condition NOT IN ('sunny', 'cloudy');
B. SELECT city, temperature, condition FROM weather WHERE condition NOT BETWEEN ('sunny', 'cloudy');
C. SELECT city, temperature, condition FROM weather WHERE condition IN ('sunny', 'cloudy');
D. SELECT city, temperature, condition FROM weather WHERE condition BETWEEN ('sunny', 'cloudy');
Answer» B. SELECT city, temperature, condition FROM weather WHERE condition NOT BETWEEN ('sunny', 'cloudy');
6.

How to select all data from student table starting the name from letter 'r'?%!

A. SELECT * FROM student WHERE name LIKE 'r%';
B. SELECT * FROM student WHERE name LIKE '%r%';
C. SELECT * FROM student WHERE name LIKE '%r';
D. SELECT * FROM student WHERE name LIKE '_r%';
Answer» B. SELECT * FROM student WHERE name LIKE '%r%';
7.

What is an SQL virtual table that is constructed from other tables?%!

A. view
B. A relation
C. Just another table
D. Query results
Answer» B. A relation
8.

The command to remove rows from a table 'CUSTOMER' is:%!

A. DROP FROM CUSTOMER ...
B. UPDATE FROM CUSTOMER ...
C. REMOVE FROM CUSTOMER ...
D. DELETE FROM CUSTOMER WHERE ...
Answer» E.
9.

The SQL keyword(s) ________ is used with wildcards.%!

A. NOT IN only
B. LIKE only
C. IN only
D. IN and NOT IN
Answer» C. IN only
10.

Which of the following do you need to consider when you make a table in SQL?%!

A. Data types
B. Primary keys
C. Default values
D. All of the above.
Answer» E.
11.

The FROM SQL clause is used to...%!

A. specify what table we are selecting or deleting data FROM
B. specify range for search condition
C. specify search condition
D. None of these
Answer» B. specify range for search condition
12.

Which of the following group functions ignore NULL values?%!

A. MAX
B. COUNT
C. SUM
D. All of the above
Answer» E.
13.

Which of the following is a SQL aggregate function?%!

A. LEFT
B. AVG
C. JOIN
D. LEN
Answer» C. JOIN
14.

Which of the following command makes the updates performed by the transaction permanent in the database?%!

A. ROLLBACK
B. COMMIT
C. TRUNCATE
D. DELETE
Answer» C. TRUNCATE
15.

Which of the following query finds the name of the sailors who have reserved at least two boats?%!

A. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid ‚Äö√¢‚Ä r2.bid
B. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND COUNT(r1.bid) > r2.bid
C. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid <> r2.bid
D. All of these
Answer» D. All of these
16.

Find the name of all cities with their temperature, humidity and countries.%!

A. SELECT city, temperature, humidity, country FROM location;
B. SELECT weather.city, temperature, humidity, country FROM weather, location;
C. SELECT weather.city, temperature, humidity, country FROM weather, location WHERE weather.city = location.city;
D. SELECT weather.city, temperature, humidity FROM weather SELECT country FROM location WHERE weather.city = location.city;
Answer» D. SELECT weather.city, temperature, humidity FROM weather SELECT country FROM location WHERE weather.city = location.city;
17.

Let the statementSELECT column1 FROM myTable;return 10 rows. The statementSELECT ALL column1 FROM myTable;will return%!

A. less than 10 rows
B. more than 10 rows
C. exactly 10 rows
D. None of these
Answer» D. None of these
18.

*$_Find the names of these cities with temperature and condition whose condition is neither sunny nor cloudy?

A. SELECT city, temperature, condition FROM weather WHERE condition NOT IN ('sunny', 'cloudy');
B. SELECT city, temperature, condition FROM weather WHERE condition NOT BETWEEN ('sunny', 'cloudy');
C. SELECT city, temperature, condition FROM weather WHERE condition IN ('sunny', 'cloudy');
D. SELECT city, temperature, condition FROM weather WHERE condition BETWEEN ('sunny', 'cloudy');
Answer» B. SELECT city, temperature, condition FROM weather WHERE condition NOT BETWEEN ('sunny', 'cloudy');
19.

*/*_Let the statementSELECT column1 FROM myTable;return 10 rows. The statementSELECT ALL column1 FROM myTable;will return?

A. less than 10 rows
B. more than 10 rows
C. exactly 10 rows
D. None of these
Answer» D. None of these
20.

*/*_Which of the following group functions ignore NULL values??

A. MAX
B. COUNT
C. SUM
D. All of the above
Answer» E.
21.

*/*_Which of the following is a SQL aggregate function??

A. LEFT
B. AVG
C. JOIN
D. LEN
Answer» C. JOIN
22.

*/*_The FROM SQL clause is used to...?

A. specify what table we are selecting or deleting data FROM
B. specify range for search condition
C. specify search condition
D. None of these
Answer» B. specify range for search condition
23.

*/*_Which of the following query finds the name of the sailors who have reserved at least two boats??

A. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid ‚Äö√¢‚Ä r2.bid
B. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND COUNT(r1.bid) > r2.bid
C. SELECT DISTINCT s.sname FROM sailors s, reserves r1, reserves r2 WHERE s.sid = r1.sid AND r1.sid = r2.sid AND r1.bid <> r2.bid
D. All of these
Answer» D. All of these
24.

*/*_Find the name of all cities with their temperature, humidity and countries.?

A. SELECT city, temperature, humidity, country FROM location;
B. SELECT weather.city, temperature, humidity, country FROM weather, location;
C. SELECT weather.city, temperature, humidity, country FROM weather, location WHERE weather.city = location.city;
D. SELECT weather.city, temperature, humidity FROM weather SELECT country FROM location WHERE weather.city = location.city;
Answer» D. SELECT weather.city, temperature, humidity FROM weather SELECT country FROM location WHERE weather.city = location.city;
25.

*/*_Which of the following command makes the updates performed by the transaction permanent in the database??

A. ROLLBACK
B. COMMIT
C. TRUNCATE
D. DELETE
Answer» C. TRUNCATE
26.

*/*_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 above
Answer» B. MODIFY TABLE
27.

*/*_What is an SQL virtual table that is constructed from other tables??

A. view
B. A relation
C. Just another table
D. Query results
Answer» B. A relation
28.

*/*_The SQL keyword(s) ________ is used with wildcards.?

A. NOT IN only
B. LIKE only
C. IN only
D. IN and NOT IN
Answer» C. IN only
29.

*/*_The command to remove rows from a table 'CUSTOMER' is:?

A. DROP FROM CUSTOMER ...
B. UPDATE FROM CUSTOMER ...
C. REMOVE FROM CUSTOMER ...
D. DELETE FROM CUSTOMER WHERE ...
Answer» E.
30.

*/*_How to select all data from student table starting the name from letter 'r'??

A. SELECT * FROM student WHERE name LIKE 'r%';
B. SELECT * FROM student WHERE name LIKE '%r%';
C. SELECT * FROM student WHERE name LIKE '%r';
D. SELECT * FROM student WHERE name LIKE '_r%';
Answer» B. SELECT * FROM student WHERE name LIKE '%r%';
31.

*/*_Which of the following do you need to consider when you make a table in SQL??

A. Data types
B. Primary keys
C. Default values
D. All of the above.
Answer» E.
32.

%_What is the meaning of LIKE '%0%0%'_%

A. Feature begins with two 0's
B. Feature ends with two 0's
C. Feature has more than two 0's
D. Feature has two 0's in it, at any position
Answer» E.
33.

_ In SQL, which command is used to change a table's storage characteristics?$?

A. ALTER TABLE
B. MODIFY TABLE
C. CHANGE TABLE
D. None of these
Answer» B. MODIFY TABLE
34.

_ If a query involves NOT, AND, OR with no parenthesis$?

A. NOT will be evaluated first; AND will be evaluated second; OR will be evaluated last.
B. NOT will be evaluated first; OR will be evaluated second; AND will be evaluated last.
C. AND will be evaluated first; OR will be evaluated second; NOT will be evaluated last.
D. The order of occurrence determines the order of evaluation.
Answer» B. NOT will be evaluated first; OR will be evaluated second; AND will be evaluated last.
35.

_ The SQL statementSELECT SUBSTR('123456789', INSTR('abcabcabc', 'b'), 4) FROM DUAL;$?

A. 6789
B. 2345
C. 1234
D. 456789
Answer» C. 1234
36.

_ Which of the following SQL commands is used to retrieve data?$?

A. DELETE
B. INSERT
C. SELECT
D. JOIN
Answer» D. JOIN
37.

_ Which of the SQL statements is correct?$?

A. SELECT Username AND Password FROM Users
B. SELECT Username, Password FROM Users
C. SELECT Username, Password WHERE Username = 'user1'
D. None of these
Answer» C. SELECT Username, Password WHERE Username = 'user1'
38.

_ What does the following query find?(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'red')MINUS(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'green')$?

A. Find the sailor IDs of all sailors who have reserved red boats but not green boats
B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats
C. Find the sailor Ids of atmost one sailor who have reserved red boats but not green boats
D. None of These
Answer» B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats
39.

_ Find the names of the countries whose condition is sunny.$?

A. SELECT country FROM location WHERE condition = 'sunny';
B. SELECT country FROM location WHERE city IN (SELECT city FROM weather WHERE condition = sunny');
C. SELECT country FROM location WHERE city NOT IN (SELECT city FROM weather WHERE condition = 'sunny');
D. SELECT country FROM location WHERE city UNION (SELECT city FROM weather WHERE condition = 'sunny');
Answer» C. SELECT country FROM location WHERE city NOT IN (SELECT city FROM weather WHERE condition = 'sunny');
40.

_ Which of the following must be enclosed in double quotes?$?

A. Dates
B. Column Alias
C. Strings
D. All of the above
Answer» C. Strings
41.

_ What operator tests column for the absence of data?$?

A. EXISTS operator
B. NOT operator
C. IS NULL operator
D. None of these
Answer» D. None of these
42.

_ Which of the following is NOT a type of SQL constraint?$?

A. PRIMARY KEY
B. ALTERNATE KEY
C. FOREIGN KEY
D. UNIQUE
Answer» C. FOREIGN KEY
43.

_ The command to eliminate a table from a database is:$?

A. DROP TABLE CUSTOMER;
B. DELETE TABLE CUSTOMER;
C. REMOVE TABLE CUSTOMER;
D. UPDATE TABLE CUSTOMER;
Answer» B. DELETE TABLE CUSTOMER;
44.

_ What SQL command can be used to add columns to a table?$?

A. ALTER TABLE TableName ADD ColumnName
B. ALTER TABLE TableName ADD COLUMN ColumnName
C. MODIFY TABLE TableName ADD ColumnName
D. MODIFY TABLE TableName ADD COLUMN ColumnName
Answer» B. ALTER TABLE TableName ADD COLUMN ColumnName
45.

_ Which of the following query is correct for using comparison operators in SQL?$?

A. SELECT name, course_name FROM student WHERE age>50 and <80;
B. SELECT name, course_name FROM student WHERE age>50 and age <80;
C. SELECT name, course_name FROM student WHERE age>50 and WHERE age<80;
D. None of these
Answer» C. SELECT name, course_name FROM student WHERE age>50 and WHERE age<80;
46.

_ The HAVING clause does which of the following?$?

A. Acts EXACTLY like a WHERE clause.
B. Acts like a WHERE clause but is used for columns rather than groups.
C. Acts like a WHERE clause but is used for groups rather than rows.
D. Acts like a WHERE clause but is used for rows rather than columns.
Answer» D. Acts like a WHERE clause but is used for rows rather than columns.
47.

_Find the temperature in increasing order of all cities$?

A. SELECT city FROM weather ORDER BY temperature;
B. SELECT city, temperature FROM weather;
C. SELECT city, temperature FROM weather ORDER BY temperature;
D. SELECT city, temperature FROM weather ORDER BY city;
Answer» D. SELECT city, temperature FROM weather ORDER BY city;
48.

_............. joins two or more tables based on a specified column value not equaling a specified column value in another table.$?

A. EQUIJOIN
B. NON-EQUIJOIN
C. OUTER JOIN
D. NATURAL JOIN
Answer» C. OUTER JOIN
49.

_Which of the following is illegal?$?

A. SELECT SYSDATE - SYSDATE FROM DUAL;
B. SELECT SYSDATE - (SYSDATE - 2) FROM DUAL;
C. SELECT SYSDATE - (SYSDATE + 2) FROM DUAL;
D. None of these
Answer» E.
50.

_Which SQL keyword is used to sort the result-set?$?

A. SORT BY
B. ORDER
C. ORDER BY
D. SORT
Answer» D. SORT