ERROR: relation with OID  25740  does not exist
SQL state: 42P01
Context: SQL statement "UPDATE best_staff SET percent = (100*count)/ $1 "
PL/pgSQL function "f_search" line  44  at SQL statement

CREATE OR REPLACE FUNCTION f_search(num_courses integer)
  RETURNS integer AS
$BODY$DECLARE
  num_discipline integer;
BEGIN

  EXECUTE
' CREATE OR REPLACE VIEW staff_count AS
	SELECT id_staff, count(id_courses)
	FROM courses_staff
	WHERE id_courses = ' || num_courses || 
	'GROUP BY id_staff
	ORDER BY id_staff';
  
  CREATE TABLE best_staff (id, name_1, name_2, name_3, count) --вот эта таблица имеет OID 25740
	 AS SELECT id, name_1, name_2, name_3, count
	 FROM staff JOIN staff_count ON (id = id_staff)
         ORDER BY count DESC;
	 

  --получение количества дисциплин для 100%
  --знания курса

  SELECT INTO num_discipline count FROM courses_count
	 WHERE id_courses = num_courses;
  
  --добаление колонки соответствия в процентах
  ALTER TABLE best_staff
	ADD percent real;

  UPDATE best_staff                             -- а ошибка фиксируется здесь
       SET percent = ( 100 *count)/num_discipline;
  

  CREATE TABLE best_want_staff (id, name_1, name_2, name_3, count, percent)
	 AS SELECT id, name_1, name_2, name_3, count, percent FROM best_staff 
	 JOIN staff_courses
	 ON (id = id_staff)
	 WHERE id_courses = num_courses
	 ORDER BY count DESC;

  RETURN num_best_staff;
END;$BODY$
  LANGUAGE 'plpgsql' VOLATILE;

CREATE OR REPLACE FUNCTION f_drop()
  RETURNS void AS
$BODY$BEGIN
DROP TABLE best_staff;        --удаление таблиц 
DROP TABLE best_want_staff;   --с результатами
END;$BODY$
  LANGUAGE 'plpgsql' VOLATILE;