SQL Queries & Data Processing is one of 10 topics in the Grade 12 Information Technology CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. What is SQL primarily used for?
Communicating with relational databases to retrieve, insert, update and delete data
Designing the physical layout of a computer motherboard
Compressing image files to save storage space
Connecting a computer to a wireless network
Answer: Communicating with relational databases to retrieve, insert, update and delete data — SQL (Structured Query Language) is the standard language for communicating with relational databases to retrieve, insert, update and delete data.
Easy
2. Why is it generally better practice to retrieve only specific named fields rather than always retrieving every field in a table?
It reduces unnecessary data transfer and makes results easier to read
It is impossible to retrieve every field from a table
It automatically increases the number of records returned
It always makes the underlying database smaller
Answer: It reduces unnecessary data transfer and makes results easier to read — Retrieving only the fields actually needed reduces unnecessary data transfer and produces results that are easier to read, especially in tables with many unrelated fields.
Medium
3. A query needs to return only records where BOTH a specific subject is Mathematics AND the mark is greater than 80. Which logical operator combines these two conditions correctly?
AND, since both conditions must be true for a record to be included
OR, since only one of the conditions needs to be true
NOT, since this reverses a single condition
No logical operator is needed for two conditions
Answer: AND, since both conditions must be true for a record to be included — The AND logical operator requires both conditions to be true simultaneously for a record to be included in the result, which matches this scenario exactly.
