Generic cursor type // generic datatype

Question

Hi,
I would like to dynamically declare a cursor in my procedure and retrieve rows from it for firing insert / update statements on another table. The procedure should take a table_name in VARCHAR2 and use it to declare a cursor like:
procedure thisProcedure (table_name in VARCHAR2) is
cursor thisCursor is select * from <table_name>;
thisRow thisCursor%ROWTYPE;
begin
loop
fetch thisCursor into thisRow
-- exit when empty
-- do sth. with this record (insert or update on another table depending on data in thisRow)
end loop;
end thisProcedure;
I have been around in several forums and have got as far as declaring a weak cursor variable (one declared without return clause) and then opening this cursor with dynamic SQL. However, the moment I want to fetch a row of that cursor into a record, I would fail as weak cursor variables do not know their ROWTYPE. So in that case, I would have the cursor correct, but I would not have the corresponding - generically and dynamically declared - datatype:
procedure thisProcedure (table_name in VARCHAR2) is
type thisCursorType is ref cursor;
thisCursor thisCursorType;
thisRow <table_name>%ROWTYPE;????
begin
open thisCursor for 'my dynamic SQL';
loop
fetch thisCursor into WHAT???????
-- exit when empty
-- do sth. with this record (insert or update on another table depending on data in thisRow)
end loop;
end thisProcedure;
Anybody know a solution or a workaround? Anything?
Cheers
Sebastian

Answer 1

Maybe you can use object types and ANYDATA/ANYTYPE types. For example:
CREATE TYPE dept_obj_type AS OBJECT (
   deptno NUMBER (2),
   dname  VARCHAR2 (20)
CREATE TABLE dept_obj_table OF dept_obj_type
CREATE TYPE emp_obj_type AS OBJECT (
   empno  NUMBER (4),
   ename  VARCHAR2 (20),
   deptno NUMBER (2)
CREATE TABLE emp_obj_table OF emp_obj_type
-- procedure inserts a "generic object type" variable
CREATE OR REPLACE PROCEDURE gen_insert1 (
   p_table   VARCHAR2,
   p_anydata ANYDATA)
IS
   l_statement VARCHAR2 (32000);
BEGIN
   l_statement :=
   '  DECLARE' ||
   '     l_anydata ANYDATA := :p_anydata;' ||
   '     l_object ' || p_anydata.GetTypeName || ';' ||
   '     l_result_code PLS_INTEGER;' ||
   '  BEGIN ' ||
   '     l_result_code := l_anydata.GetObject (l_object);' ||
   '     INSERT INTO ' || p_table || ' VALUES (l_object);' ||
   '  END;';
   EXECUTE IMMEDIATE l_statement USING IN p_anydata;
END;
-- unnamed PL/SQL block for testing
DECLARE
   l_dept dept_obj_type;
   l_emp  emp_obj_type;
BEGIN
   -- creates objects
   l_dept := dept_obj_type (10, 'dept 10');
   l_emp  := emp_obj_type (2000, 'emp 2000', 10);
   -- inserts objects
   gen_insert1 (
      p_table   => 'dept_obj_table',
      p_anydata => ANYDATA.ConvertObject (l_dept));
   gen_insert1 (
      p_table   => 'emp_obj_table',
      p_anydata => ANYDATA.ConvertObject (l_emp));
END;
/For (very complicated) relational version see
Inserting a "Generic Record Type" Using ANYDATA/ANYTYPE Types
http://www.quest-pipelines.com/pipelines/plsql/tips04.htm#MARCH
Regards,
Zlatko Sirotic