Can you reference an aggregate function on a temporary row in an insert statement within a stored procedure in postgresql? - postgresql-11

Question

I am writing a postgres stored procedure that loops through the rows returned from a select statement. For each row it loops through, it inserts values from that select statement into a new table. One of the values I need to insert into the second table is the average of a column. However, when I call the stored procedure, I get an error that the temporary row has no attribute for the actual column that I am averaging. See stored procedure and error below.
Stored Procedure:
create or replace procedure sendToDataset(sentence int)
as $$
declare temprow peoplereviews%rowtype;
BEGIN
FOR temprow IN
select rulereviewid, avg(rulereview)
from peoplereviews
where sentenceid = sentence
group by rulereviewid
loop
insert into TrainingDataSet(sentenceId, sentence, ruleCorrectId, ruleCorrect, dateAdded)
values(sentence, getSentenceFromID(sentence), tempRow.rulereviewid, tempRow.avg(rulereview), current_timestamp);
END LOOP;
END
$$
LANGUAGE plpgsql;
Error:
ERROR: column "rulereview" does not exist
LINE 2: ...omID(sentence), tempRow.rulereviewid, tempRow.avg(rulereview...
^
QUERY: insert into TrainingDataSet(sentenceId, sentence, ruleCorrectId, ruleCorrect, dateAdded)
values(sentence, getSentenceFromID(sentence), tempRow.rulereviewid, tempRow.avg(rulereview), current_timestamp)
CONTEXT: PL/pgSQL function sendtodataset(integer) line 11 at SQL statement
SQL state: 42703
Basically, I am wondering if it's possible to use that aggregate function in the insert statement or not and if not, if there is another way around it.

Answer 1

you don't need to use a slow and inefficient loop for this:
insert into TrainingDataSet(sentenceId, sentence, ruleCorrectId, ruleCorrect, dateAdded)
select getSentenceId(sentence), sentence, rulereviewid, avg(rulereview), current_timestamp
from peoplereviews
where sentenceid = sentence
group by rulereviewid
To answer the original question: you need to provide a proper alias for the aggregate:
FOR temprow IN
select rulereviewid, avg(rulereview) as avg_views
from peoplereviews
where sentenceid = sentence
group by rulereviewid
loop
insert into TrainingDataSet(sentenceId, sentence, ruleCorrectId, ruleCorrect, dateAdded)
values(sentence, getSentenceFromID(sentence), tempRow.rulereviewid,
tempRow.avg_views, current_timestamp);
END LOOP;