On 10/7/24 08:15, PetSerAl wrote:
How to reliable get cursor name which cause invalid_cursor_name error?
postgres=# CREATE FUNCTION value_from_cursor_unsafe(cursor_name text)
RETURNS integer
postgres-# STRICT LANGUAGE plpgsql
postgres-# AS $$
postgres$# DECLARE
postgres$# cursor CONSTANT refcursor NOT NULL := cursor_name;
postgres$# result integer;
postgres$# BEGIN
postgres$# FETCH FIRST FROM cursor INTO result;
postgres$# return result;
postgres$# END
postgres$# $$;
CREATE FUNCTION
postgres=# CREATE FUNCTION value_from_cursor_safe(cursor_name text)
RETURNS integer
postgres-# STRICT LANGUAGE plpgsql
postgres-# AS $$
postgres$# DECLARE
postgres$# result integer;
postgres$# BEGIN
postgres$# BEGIN
postgres$# result := value_from_cursor_unsafe(cursor_name);
postgres$# EXCEPTION
postgres$# WHEN invalid_cursor_name THEN
postgres$# RAISE INFO '%', SQLERRM;
postgres$# END;
postgres$# return result;
postgres$# END
postgres$# $$;
CREATE FUNCTION
postgres=# SELECT value_from_cursor_safe('asd'); -- case 1
INFO: cursor "asd" does not exist
value_from_cursor_safe
------------------------
FYI, if you do \ef value_from_cursor_unsafe the function definition will
appear in an editor and from there you can copy and paste to make the
output easier to follow.
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
