odwiedziny w danym okresie z możliwością wyboru kategorii czytelników
SELECT count(*)
FROM (
SELECT statistics.borrowernumber as czytelnikow, statistics.type FROM statistics, items, borrowers
WHERE items.itemnumber = statistics.itemnumber
and DATE(statistics.datetime)>=<<Data od (yyyy-mm-dd)|date>>
and DATE(statistics.datetime)<=<<Data do (yyyy-mm-dd)|date>>
and `items`.`homebranch` = <<Biblioteka|branches>>
and `statistics`.`borrowernumber` IS NOT NULL
and `statistics`.`borrowernumber` =borrowers.`borrowernumber`
and
borrowers.categorycode=<<Kategoria czytelnika|categorycode>>
GROUP BY statistics.borrowernumber )AS t1
