CREATE OR REPLACE FUNCTION men_visited(fromdate "timestamp", todate "timestamp")
  RETURNS int4 AS
$BODY$
DECLARE
result int;
char_ids varchar[];
int_ids int[];
counter int;
current_id int;
BEGIN

select ARRAY(select distinct patient_id from rooms WHERE entered_in>=fromDate AND entered_in<=toDate 
  
   ) into int_ids;  //здесь летит ошибка, а как верно записать не знаю :(

  result=array_upper(int_ids, 1 );

select ARRAY(select distinct patient_id from note WHERE date>=fromDate AND date<=toDate) into char_ids;
  WHILE(counter<=array_upper(char_ids, 1 )
    LOOP
    SELECT id_patient WHERE id=char_ids[counter] into current_id;
    //и вот здесь нужно проверить, существует ли уже current_id в массиве int_ids, но как это       //сделать не могу найти. Просто в цикле проверять? - как-то некрасиво все получается...


return result;
END
$BODY$
  LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION men_visited(fromdate "timestamp", todate "timestamp") OWNER TO root;

CREATE TABLE wardpatients
(
  id int4 NOT NULL DEFAULT nextval('wardpatients_id_seq'::regclass), -- primary key and unique identifier of the connection
  ward_id int4 NOT NULL, -- reference to the wards -> id (foreign key)
  patient_id int4 NOT NULL, -- reference to the patients -> id_patient (foreign key)
  admitted_on timestamp NOT NULL, -- date and time when the patient was admitted to the ward
  deposit numeric( 15 , 2 ) NOT NULL, -- deposit the patient pays in advance for being admitted
  deposit_pay_type char( 1 ), -- deposit type of payment
  extra_rate_per_day numeric( 15 , 2 ) NOT NULL, -- extra charges per day
  extra_tax1 numeric( 15 , 2 ) NOT NULL, -- tax 1 on extra charges per day
  extra_tax2 numeric( 15 , 2 ) NOT NULL -- tax 2 on extra charges per day
}

CREATE TABLE note
(
  note_string text,
  "index" int4 NOT NULL, -- Seriar number of the note (starts from 1).
  patient_id varchar( 40 ) NOT NULL, -- Foreign key reference to the patient table.
  date timestamp NOT NULL, -- Date and time this note image was inserted or last modified.
  id int4 NOT NULL DEFAULT nextval('note_id_seq'::regclass), -- Unique identifier of the note
  origin int2 NOT NULL DEFAULT  0 , -- Origin of this patient history record. This is a new value, so old records will have Patient History origin (0).
  doctor_id int4, -- Doctor who created this record. NULL means the doctor is unknown.
  lab_form_title varchar( 40 ),
  disease_code_id int4,
  surgery_code_id int4
}

CREATE TABLE patient
(
  id varchar( 80 ) NOT NULL,  --варчаровский id
  ....
  id_patient int4 NOT NULL DEFAULT nextval('patient_id_patient_seq'::regclass), --int id
   ...

SELECT count(SELECT distinct patient.id, patient.id_patient
from patient
join wardpatients on ( wardpatients.patient_id = patient.id_patient )
join note on ( note.patient_id = patient.id )
where wardpatients.admitted_on between fromdate and todate
and note.date between fromdate and todate);