Question

Which of the following is not an aggregate function in SQL ?

• A. COUNT(*)
• B. MIN()
• C. LEFT()
• D. AVG()

Hint:

Remember — string functions like LEFT(), RIGHT(), and SUBSTRING() work on each row, not on groups of rows.

Answer 1

The Correct Option is C

In SQL, aggregate functions perform a calculation on a set of values and return a single value as a result.
Common aggregate functions include COUNT(), MIN(), MAX(), SUM(), and AVG().
- COUNT(*) returns the total number of rows.
- MIN() returns the smallest value from a group.
- AVG() calculates the average of numeric values.
However, LEFT() is not an aggregate function.
LEFT() is a string function used to extract a specified number of characters from the left side of a string.
It operates row by row and does not summarize data across multiple rows.
Therefore, among the options given, LEFT() is the only one that is not an aggregate function.