Which of the following is an aggregate function in SQL?
a) COUNT()
b) INSERT()
c) DELETE()
d) ALTER()
Answer:
a) COUNT()
Explanation:
COUNT() is an aggregate function in SQL that returns the number of rows that match a specified condition. It is commonly used to count rows in a table or the number of non-null values in a column.
Other aggregate functions in SQL include SUM(), AVG(), MAX(), and MIN(), all of which perform calculations on a set of values and return a single result.
Aggregate functions are often used with the GROUP BY clause to summarize data in reports and analyses.