An aggregate function derives it value from an aggregation, or group, of values. A data manipulation function (also known as a "scalar function") derives its value from a single column value. For example, we can convert a character column value to all uppercase or lowercase.
To learn how work with data manipulation functions in a SQL select statement, follow these steps:
upperdata manipulation function returns its argument in upper case. The
lowerdata manipulation function returns its argument in lower case.