SQL Group-By Expressions

An SQL Group-By expression is simply a comma-delimited list of Value Expressions.

Extra functions and variables available when executing group by expressions

When executing a group by expression, the following extra fuctions and variables are available:

• The expressions that were used in the group by clause. For example, if you group on label,value, then you can access label and value within the expression.
• The rowName() function will be a string version of the JSON encoded array of grouping fields. This is the default value of the row.
• The groupKeyElement(n) or group_key_element(n) function takes an integer index and returns the value of that element of the group expression. So if the expression was grouped by label, value * 10, then group_key_element(0) will have the value of the expression label, and group_key_element(1) will have the value of the expression value * 10.