Sending result of Procedure as the body of an email - oracle

Question

I have a procedure which returns a set of rows.
Similarly, I am using a procedure to send an email whose parameters is as follows :
SEND_MAIL ( mail_to, mail_from, mail_subject, mail_body, host)
I have been trying to pass a variable which consists of the result from the DBMS_OUTPUT.PUT_LINE as mail subject in the SEND_MAIL procedure but I am only obtaining the last record of the result which indicates the variables only has the latest inserted value.
I want to receive the entire result in the mail body.
create OR REPLACE PROCEDURE EVAL_LOG AS
mail_body_v varchar2(4000);
BEGIN
FOR I IN ( select LOG.LOG_DATE,LOG.ACTION,LOG.OLD,LOG.NEW from
dw.EVALUATIONS_LOG LOG
where to_char(log_date,'DD-MON-YYYY')
in (select max(to_char(log_date,'DD-MON-YYYY')) from dw.EVALUATIONS_LOG))
loop mail_body_v:=
DBMS_OUTPUT.PUT_LINE (
( 'Date : ' || i.log_date
|| ' ACTION : ' || i.ACTION
|| ' OLD : ' || i.OLD
|| ' NEW : ' || i.NEW));
end loop;
SEND_MAIL('****#mailid.com',
'Subject',mail_body_v,'****#mailid.com','host');
end;
Output:
Date : 16-AUG-22 ACTION : INSERT OLD : NEW : 2382382
Date : 16-AUG-22 ACTION : UPDATE OLD : 175 NEW : 195
Date : 16-AUG-22 ACTION : INSERT OLD : NEW : 232323
Date : 16-AUG-22 ACTION : UPDATE OLD : 195 NEW : 175
Date : 16-AUG-22 ACTION : UPDATE OLD : 195 NEW : 175
Date : 16-AUG-22 ACTION : UPDATE OLD : 175 NEW : 195
Date : 16-AUG-22 ACTION : DELETE OLD : 232323 NEW :

Answer 1

You are overwriting value of mail_body_v each time you enter loop, thats why only the last result is visible.
Instead of assigning new value to the mail_body_v each time it enters the loop, you should add text to the old value.
So instead of: mail_body_v:= DBMS_OUTPUT...
you should do it like that: mail_body_v:= mail_body_v || DBMS_OUTPUT...
Your code, after required changes could look like:
CREATE OR REPLACE PROCEDURE EVAL_LOG AS
mail_body_v varchar2(4000);
BEGIN
FOR I IN ( select LOG.LOG_DATE,LOG.ACTION,LOG.OLD,LOG.NEW from
dw.EVALUATIONS_LOG LOG
where to_char(log_date,'DD-MON-YYYY')
in (select max(to_char(log_date,'DD-MON-YYYY')) from dw.EVALUATIONS_LOG))
loop
mail_body_v:= mail_body_v ||
DBMS_OUTPUT.PUT_LINE (
( 'Date : ' || i.log_date
|| ' ACTION : ' || i.ACTION
|| ' OLD : ' || i.OLD
|| ' NEW : ' || i.NEW));
end loop;
SEND_MAIL('****#mailid.com',
'Subject',mail_body_v,'****#mailid.com','host');
end;