Is it possible to parameterize a query inside pl sql?
-
19-08-2019 - |
Question
The stored procedures being written here currently concats the parameters to the queries:
SELECT *
FROM Names
WHERE Name = ' || prmName || '
ORDER BY ' || prmSortField
Is it possible to parameterize this query inside the stored procedure? Possibly like:
query = 'select * From Names Where Name = @name Order By ' || prmSortField
call(query, prmName)
Note:
In case you wonder why we do so, there are two common parameters for our sp's: sortFieldIndex
and sortDirection
. Since we cannot directly parameterize these, the query is dynamically generated. But other parameters make the queries open for injection. So I am looking a way to parameterize some of the parameters.
Solution
Absolutely. Use cursors.
DECLARE
CURSOR c1 (job VARCHAR2, max_wage NUMBER) IS
SELECT * FROM employees WHERE job_id = job AND salary > max_wage;
BEGIN
FOR person IN c1('CLERK', 3000)
LOOP
-- process data record
DBMS_OUTPUT.PUT_LINE('Name = ' || person.last_name || ', salary = ' ||
person.salary || ', Job Id = ' || person.job_id );
END LOOP;
END;
OTHER TIPS
For a dynamic query with bind values, do this:
procedure p (prmName varchar2, prmSortField varchar2)
is
query varchar2(100);
rc sys_refcursor;
names_rec names%rowtype;
begin
query = 'select * From Names Where Name = :name Order By ' || prmSortField
open rc for query using prmName;
loop
fetch rc into names_rec;
exit when rc%notfound;
-- process this row
end loop;
close rc;
end;
For a more elaborate procedure that supports optional parameter values (but uses sys context), check out the following post on Asktom.com
Licensed under: CC-BY-SA with attribution
Not affiliated with StackOverflow