问题
With the latest update of PostgreSQL supporting procedures. The official blog, quoted that "As opposed to functions, procedures are not required to return a value." (https://blog.2ndquadrant.com/postgresql-11-server-side-procedures-part-1/)
So my question is, is there actually any way for me to return error code or response in a procedure? (Procedures is rather new in Postgres thus there were very little resources online.)
Here is an example of what I meant by returning these "error codes"
create or replace PROCEDURE multislot_Update_v1
(
p_id in varchar2,
p_name in varchar2,
p_enname in varchar2,
results out SYS_REFCURSOR
) AS
rowNumber int;
defaultNumber int;
BEGIN
select count(1) into rowNumber from MULTISLOTSGAME where fid=P_id;
if (rowNumber = 0) then
open results for
select '1' as result from dual;
return;
end if;
update MULTISLOTSGAME set
name = P_name,
enname = P_enname
where fid = P_id ;
commit;
open results for
select '0' as result, t1.* from MULTISLOTSGAME t1 where fid = p_id;
END multislot_Update_v1;
The above script is an Oracle procedure, as u can see if the returned result is "1" it meant that the update wasn't successful.
Is there any way I can write the above script (with error code) as a PostgresSQL Procedure ? Maybe an example of using the "INOUT" argument would be great!
回答1:
You can have INOUT
parameters in a procedure.
You call a procedure with the CALL statement; if there are any INOUT
parameters, the statement will return a result row just like SELECT
.
Here is an example that uses a procedure that returns a refcursor
:
CREATE PROCEDURE testproc(INOUT r refcursor) LANGUAGE plpgsql AS
$$BEGIN
r := 'cur';
OPEN r FOR VALUES (1), (42), (12321);
END;$$;
BEGIN;
CALL testproc(NULL);
r
-----
cur
(1 row)
FETCH ALL FROM cur;
column1
---------
1
42
12321
(3 rows)
COMMIT;
回答2:
How about using the RAISE statement?
https://www.postgresql.org/docs/10/static/plpgsql-errors-and-messages.html
来源:https://stackoverflow.com/questions/50940438/postgresql-11-procedures