SQL not properly ended? - sql

Question

I know i don't have to use SQL but i have other code between declare begin and end . I just extracted this part and everything works except this . I get the following error:
Error report:
ORA-06550: line 5, column 5:
PL/SQL: ORA-00933: SQL command not properly ended
ORA-06550: line 3, column 5:
PL/SQL: SQL Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
This is the code:
DECLARE
BEGIN
UPDATE octombrie
SET nr_imprumut = I.nr
from (select book_date bd,count(book_date) nr
from rental
where to_char(book_date,'mm') like '10'
group by book_date) I
where data = I.bd;
END;
/
I don't get it what did i do wrong ?
EDIT: book_date will give me a day from the month of october. In that day multiple books are rented, so i find out how many books i rented by counting the number of times the same date apears (the rented books are in the rental table). I then take this data and Update October table(i put the number of books aka 'nr' where the date in the october table matches the date in which the books where rented);

Answer 1

DECLARE
BEGIN
UPDATE octombrie o
SET o.nr_imprumut =
(select count(r.book_date)
from rental r
where to_char(r.book_date,'mm') like '10' and o.data = r.book_date)
WHERE exists (select 1 from rental r
where to_char(r.book_date,'mm') like '10' and o.data = r.book_date);
END;
Use
where exists (select 1 from rental r
where to_char(r.book_date,'mm') like '10' and o.data = r.book_date)
if you want to update only those rows for which you found something in rental (otherwise ALL rows will be updated in octombrie)
Another variant (updates all October 2014 data in octombrie; for each data calculates the number of rental ON this data)
UPDATE octombrie o
SET o.nr_imprumut =
(select count(r.book_date)
from rental r
where r.book_date between trunc(o.data) and trunc(o.data) + 1 - 1/24/60/60)
WHERE o.data between to_date('2014-10-01','yyyy-mm-dd') and to_date('2014-10-31 23:59:59','yyyy-mm-dd hh24:mi:ss');

Answer 2

I guess you really wanted to something like that:
DECLARE
BEGIN
UPDATE octombrie o
SET o.nr_imprumut =
(SELECT count(1)
FROM rental r
WHERE r.book_date between o.data and o.data+1-1/86400)
WHERE data between to_date('2014-10-01','yyyy-mm-dd') and to_date('2014-10-31','yyyy-mm-dd');
END;
Note that the WHERE-clause of the UPDATE-statement specifies a year, I don't think you want to updated your records for all days in any october. Limiting the date like that (with a BETWEEN operator, but without a TO_CHAR) makes it possible to use an index on octombrie.data, something I hope you have.