Minor Description
when i enter below query,
select substr(r_reason_desc,1,20) ,avg(ws_quantity) ,avg(wr_refunded_cash) ,avg(wr_fee) from [...] where [...] group by r_reason_desc order by substr(r_reason_desc,1,20) ,avg(ws_quantity) ,avg(wr_refunded_cash) ,avg(wr_fee) limit 100;
this error is occured.
ERROR: Cannot evaluate the field "?substr" at node (12)
so, I editted GROUP BY clause like below then run correctly.
select substr(r_reason_desc,1,20) ,avg(ws_quantity) ,avg(wr_refunded_cash) ,avg(wr_fee) from [...] where [...] group by substr(r_reason_desc,1,20) order by substr(r_reason_desc,1,20) ,avg(ws_quantity) ,avg(wr_refunded_cash) ,avg(wr_fee) limit 100;