SQL functions

The SQL language provides a number of built-in functions, such as UCASE() and COUNT(). These functions fall into three categories:

These functions fall into three categories:

Scalar Functions that take zero or more data arguments and return a single data result per input row.
Table Functions that take zero or more data arguments and return a table result. The returned table can contain a number of rows less than, equal to, or greater than the number of input rows.
Aggregate Functions that take one or more data arguments and return a single value per group or window, and grand aggregates return a single result for all the data.

In this guide, these built-in functions are referred to as SQL functions.