A Level Computer Science OCR Practice Exam

Which of these SQL components would you typically use to restrict the number of records returned by a query?

1. SELECT

2. FROM

3. WHERE

4. ORDER BY

The correct answer is: WHERE

The component used to restrict the number of records returned by a query is the WHERE clause. It allows you to specify conditions that the data must meet to be included in the results. For example, if you want to retrieve only records where a specific column's value meets a certain criterion (like a certain age, status, or category), you would implement that condition within the WHERE clause. Using WHERE ensures that only the relevant records that satisfy the defined criteria are returned from the database. Without it, a query would return all records from the specified tables, which may not be useful, especially in large datasets. The other options play different roles in an SQL query. SELECT is used to specify which columns you want to retrieve, FROM indicates the source tables for the data, and ORDER BY is used to sort the results based on specified columns, rather than limiting the number of records returned.