introduction to sql

Which SQL function is used to count the number of rows in a SQL query?

• COUNT NUMBER()

• NUMBER()

• SUM()

• COUNT(*)

If you don’t specify ASC or DESC after a SQL ORDER BY clause, the following is used by default

• ASC

• DESC

• There is no default value

• None of the mentioned

With SQL, how do you select all the records from a table named “Persons” where the value of the column “FirstName” ends with an “a”?

• SELECT * FROM Persons WHERE FirstName=’a’

• SELECT * FROM Persons WHERE FirstName LIKE ‘a%’

• SELECT * FROM Persons WHERE FirstName LIKE ‘%a’

• SELECT * FROM Persons WHERE FirstName=’%a%’

What does the ALTER TABLE clause do?

• The SQL ALTER TABLE clause modifies a table definition by altering, adding, or deleting table columns and/or constraints

• The SQL ALTER TABLE clause is used to insert data into database table

• THE SQL ALTER TABLE deletes data from database table

• The SQL ALTER TABLE clause is used to delete a database table

How can you change “Hansen” into “Nilsen” in the “LastName” column in the Persons table?

• UPDATE Persons SET LastName=’Hansen’ INTO LastName=’Nilsen’

• MODIFY Persons SET LastName=’Nilsen’ WHERE LastName=’Hansen’

• MODIFY Persons SET LastName=’Hansen’ INTO LastName=’Nilsen’

• UPDATE Persons SET LastName=’Nilsen’ WHERE LastName=’Hansen’

SQL query to find all the cities whose humidity is 95.

• SELECT city WHERE humidity = 95

• SELECT city FROM weather WHERE humidity = 95

• SELECT humidity = 89 FROM weather

• SELECT city FROM weather

SQL query to find the temperature in increasing order of all cities.

• SELECT city FROM weather ORDER BY temperature

• SELECT city, temperature FROM weather

• SELECT city, temperature FROM weather ORDER BY temperature

• SELECT city, temperature FROM weather ORDER BY city

The command to remove rows from a table ‘CUSTOMER’ is __________________

• DROP FROM CUSTOMER

• UPDATE FROM CUSTOMER

• REMOVE FROM CUSTOMER

• DELETE FROM CUSTOMER WHERE

Find the name of those cities with temperature and condition whose condition is either sunny or cloudy but temperature must be greater than 70.

• SELECT city, temperature, condition FROM weather WHERE condition = ‘sunny’ AND condition = ‘cloudy’ OR temperature > 70

• SELECT city, temperature, condition FROM weather WHERE condition = ‘sunny’ OR condition = ‘cloudy’ OR temperature > 70

• SELECT city, temperature, condition FROM weather WHERE condition = ‘sunny’ OR condition = ‘cloudy’ AND temperature > 70

• SELECT city, temperature, condition FROM weather WHERE condition = ‘sunny’ AND condition = ‘cloudy’ AND temperature > 70

How many records would be returned by the following SQL "SELECT * FROM songs WHERE TimesPlayed >=3

• 0

• 2

• 3

• 4