Name

count() — Count the number of rows

Common Usage

count( expression )
count( * )

Description

The count() aggregate counts the number of rows with a non-NULL expression . If expression is given as an asterisk character (*), the total number of rows in an aggregate group will be returned, regardless of value. In some situations, the computation for the count( * ) syntax can be optimized and the result value can be computed without an actual data scan.

See Also

sum(), total()