Execute a Select inside a loop PL/SQL and return cursor? - sql

Question

This is probably a simple question for who knows PL/SQL.
I have a stored procedure who takes an array of varchar in input:
TYPE MULTI is table of VARCHAR(15) index by BINARY_INTEGER;
PROCEDURE MYPROC(
SINGLE IN MULTI,
P_RESULT OUT MY_PCK.MYCURSOR,
P_SOMETHING OUT VARCHAR2,
);
The cursor works because i have tested it in other cases but this is the first with an array parameter.
I have a problem with the body, how can i assign each value i get from the select to the cursor?
BEGIN
FOR i IN SINGLE.first .. SINGLE.last
LOOP
--BEGIN OPEN P_RESULT FOR this --this on left gives me error
SELECT MT.DESCR INTO P_SOMETHING
FROM MYTABLE1 MT
WHERE MT.IDS = SINGLE(i)
AND and rownum < 2;
--dbms_output.put_line(SINGLE(i)); --if i use this instead of select i get the values i send to this procedure.
END LOOP;
i tried also:
SELECT MT.DESCR INTO P_RESULT but gives error
What i'm doing wrong?
Thanks in advice.

Answer 1

You can't use your PL/SQL collection type in a SQL statement in 11g. You could create a SQL collection type, or find one you already have access to (which has a suitable string length) and use that to at least verify the mechanism.
For instance, this uses a local variable of type SYS.HSBLKNAMLST, which is defined as a table of varchar2(30), more than enough to match your own PL/SQL type's string length. That variable is populated from your passed-in PL/SQL type, and that is then used in a query to open the cursor:
PROCEDURE MYPROC(
SINGLE IN MULTI,
P_RESULT OUT MY_PCK.MYCURSOR
) IS
LOCAL_COLL SYS.HSBLKNAMLST := SYS.HSBLKNAMLST();
BEGIN
FOR i IN SINGLE.first .. SINGLE.last
LOOP
LOCAL_COLL.extend();
LOCAL_COLL(LOCAL_COLL.last) := SINGLE(i);
END LOOP;
OPEN P_RESULT FOR
SELECT MT.DESCR
FROM MYTABLE1 MT
LEFT JOIN TABLE(LOCAL_COLL) LC
ON LC.COLUMN_VALUE = MT.IDS
WHERE LC.COLUMN_VALUE IS NULL;
END;
I'm a bit confused about the query you showed in your loop though; you seem to be attempting to re-open the cursor for each element of the array, though maybe you were trying to append the result of the query for each element to the same cursor - thought the != would mean that all rows would be included at some point. I've guess that you're trying to get all records with IDS values that are not in the array. If you actually want all that are then that would be:
OPEN P_RESULT FOR
SELECT MT.DESCR
FROM TABLE(LOCAL_COLL) LC
JOIN MYTABLE1 MT
ON MT.IDS = LC.COLUMN_VALUE;
You can see which built-in types are available to you by querying the data dictionary, e.g:
select owner, type_name, coll_type, elem_type_name, length
from all_coll_types
where elem_type_name = 'VARCHAR2'
and coll_type = 'TABLE'
and owner = 'SYS'
order by length;
It would be preferable to create your own SQL type if you're able to.