Currently, the default aggregation type of string type field is
set to count, and it cannot be changed to any other aggregation type while
binding it in values. So, provide an option to change the aggregation of string
type fields. The following consideration needs to be considered like Microsoft
1. The aggregation type of string type field can be changed.
2. String(null) and numeric data type combination for same field
should be considered for values.
3. String(null) type data do not involve in the aggregation when
the field has number and string type combination.