How to update nested table records ??

Question

Hi, I am just starting to write anything in PL/SQL and having some difficulties with basic syntax. Thanks for any help in advance.
My problem is how to update collection (nested table of objects) with SQL statement. My nested table is not a column of regular table.
Example:
CREATE OR REPLACE TYPE tmpRec AS OBJECT(
Col1 INT,
Col2 INT
CREATE OR REPLACE TYPE tmpTable IS TABLE OF tmpRec;
DECLARE v tmpTable :=
tmpMBATable(
tmpRec(1,1),
tmpRec(2,2),
tmpRec(3,3),
BEGIN
--UPDATE TABLE(CAST(v AS tmpTable)) T SET T.Col2 = 1 WHERE T.Col1 =1;
--UPDATE TABLE(v) T SET T.Col2 = 12 WHERE T.Col1 =1;
--UPDATE (SELECT * FROM TABLE(v) )T SET T.Col2 = 12 WHERE T.Col =1;
END;
I am getting either
PL/SQL: ORA-22841: DML is not allowed on PL/SQL Collections
OR
PL/SQL: ORA-00903 Bad table name.
I found there is no problem when collection is a column of DB table (UPDATE TABLE(select collection_column from table) T SET T.Col2 = 12 WHERE T.Col1 =1;) but i want it to be just a collection without storing it in DB, is it possible ?
Please help.

Answer 1

898539 wrote:
Thanks, for fast answer but my problem is more complex, maybe you can show me some workaround i try to use collection but maybe i should do something else...A complex problem does not mean a complex solution. In fact, complex problems should ideally be solved by breaking the complexity down into simpler components and then solving each of these in turn.
As far as nested tables go? An interesting feature. But one that I will need a lot of convincing and justification for to consider for a production system. There are some major limitations with using nested tables. And these do not exist when using the simpler form of a standard relational child table instead.
I am migrating from Sybase Adaptive Server Enterprise and searching for sollution for something we used temporary tables for so far.Temporary tables in Sybase are typically used to prevent concurrency issues (readers and writers blocking one another). Thus make a temp copy of the data and do not prevent concurrent access to the source data itself.
These reasons simply do not exist in Oracle. In most cases, using temporary tables in Oracle simply because that is how it was implemented in Sybase, would be fundamentally flawed.
Oracle is not Sybase. It does a very poor imitation of Sybase.
I need a collection that can store some data and I need to be able to use it as a table so I can join to it via SQL query or call some DML on it.Why do you need a collection? The best place for data in Oracle is inside a table. Not inside a collection - especially not if that collection resides in PGA memory in the PL/SQL engine.
In my store procedure I am updating, deleteing and inserting some data to it depends on context.What context? Oracle supports context namespaces - often used for virtual private database (VPDB) implementations. If you are referring to scope instead - there are a number of ways that Oracle supports scope too.
The bottom line is that you should not approach this problem with "+how do I convert this Sybase method into an Oracle method+". Instead you need to look at the business requirement that the Sybase method addresses and then determine how best to address that requirement using Oracle.