PostgreSQL Macro Query

Hi there,

I have written some code to calculate basic summary stats and wish to then incorporate this code within a macro... I want to run the code many multiple times and define the variables (on which the summary statistics are calculated) outside of the basic code. 

For example, see some very basic code below... I would use a macro so that I don’t have to change ‘STUDY_GROUP’ in the code each time.

select "STUDY_GROUP" , count("STUDY_GROUP")

from "TABLE1" group by "STUDY_GROUP";

Many thanks in advance,