IGCSE Quiz -- Focus on SQL, Programming, and Hardware

What is the purpose of the following pseudocode:

SET Total = 0

FOR i = 1 TO 5

SET Total = Total + i

NEXT i

• To calculate the sum of numbers 1 to 5
• To multiply numbers 1 to 5
• To count from 1 to 5
• To print numbers 1 to 5

Answer explanation

This pseudocode initializes Total to 0 and uses a FOR loop to add each number from 1 to 5 to Total, resulting in 15.

Which pseudocode statement assigns the value 10 to a variable named x?

• x = 10
• SET x TO 10
• x := 10
• All of the above

Answer explanation

In pseudocode, assignment can be written in various forms depending on the convention, but all these options correctly assign 10 to x.

What will the output be for this pseudocode: SET x = 3 IF x > 0 THEN OUTPUT 'Positive' ELSE OUTPUT 'Negative' ENDIF

• Positive
• Negative
• 3

Answer explanation

Since x is 3, which is greater than 0, the IF condition is true, and 'Positive' is output.

Which of these are valid pseudocode loop structures?

• FOR...TO...NEXT
• WHILE...DO...ENDWHILE
• REPEAT...UNTIL
• IF...THEN...ELSE

Answer explanation

FOR, WHILE, and REPEAT are all valid loop structures in pseudocode, while IF is a conditional statement.

Complete this pseudocode to output numbers 1 to 10: FOR i = 1 TO (a)   OUTPUT i NEXT i

Answer explanation

The FOR loop needs a start value of 1 and an end value of 10 to output numbers 1 to 10.

What is the purpose of a primary key in a database?

• To store duplicate records
• To uniquely identify each record
• To sort the database
• To encrypt data

Answer explanation

A primary key ensures each record in a table is uniquely identifiable.

Which SQL query selects all students from a table named 'Students' where the grade is 'A'?

• SELECT * FROM Students WHERE grade = 'A'
• SELECT grade FROM Students WHERE 'A'
• SELECT * FROM Students WHERE grade > 'A'
• SELECT * FROM grade WHERE Students = 'A'

Answer explanation

The correct syntax uses SELECT * to retrieve all columns, FROM specifies the table, and WHERE filters by grade = 'A'.

In SQL, what does the asterisk (*) represent in a SELECT statement?

• All columns
• All rows
• A specific column
• A specific row

Answer explanation

The asterisk (*) is a wildcard that represents all columns in the table.

Which of these SQL commands are used to retrieve data?

• SELECT
• INSERT
• UPDATE
• DELETE

Answer explanation

SELECT retrieves data, while INSERT, UPDATE, and DELETE modify data.

Write an SQL query to find all records in a table 'Books' where the author is 'Smith'

(a)  

Answer explanation

This query selects all columns from the Books table where the author field equals 'Smith'.