for many reasons, we are protecting our Intellectual Property at its greatest and we already obfuscate and wrap our logic. Everything runs fine.
We have a concern about the views. In some cases we give to our clients some views based on their specific needs. That way we can offer 'em the right results. Otherwise, they sometimes try to build their own sql and they get wrong answers.
Is it possible to fill a materialized view based on a package or procedure? I understand that only a function can return something but I am maybe missing something. My actual alternative is to fill a table via a procedure but I am uncomfortable with that.
We are actually using Oracle 11
Any idea is welcome. Thanks!
You can provide a function which retruns a Nested Table.
CREATE TABLE SECRET_TABLE (col_1 NUMBER, col_2 VARCHAR2(10));
CREATE OR REPLACE TYPE t_secret_table_rec AS OBJECT (col_1 NUMBER, col_2 VARCHAR2(10));
CREATE OR REPLACE TYPE t_secret_table AS TABLE OF t_secret_table_rec;
CREATE OR REPLACE FUNCTION GetData RETURN t_secret_table AS
res t_secret_table;
BEGIN
-- Wrap this function
SELECT t_secret_table_rec(col_1, col_2)
BULK COLLECT INTO res
FROM SECRET_TABLE;
RETURN res;
END;
Then you can select the data like this:
SELECT * FROM TABLE(GetData);
However, it's quite some effort and you may face some problems regarding performance.
Related
I'm making a procedure inside an Oracle Form that calls a backtracking which inserts in a table (the solution table). That backtracking is fed by a varray (ítem_array) of ítems (beans). Problem is the compiler says that there is no function name ítem.
existing objects in the database:
CREATE TYPE item IS object( NUM_OPERACIO NUMBER, TITULS NUMBER);
CREATE TYPE item_array IS VARRAY(1000) OF item;
create table my_table (NUM_OPERACIO NUMBER, TITULS NUMBER);
insert into my_table ( NUM_OPERACIO,TITULS ) values (1,10);
insert into my_table ( NUM_OPERACIO,TITULS ) values (2,20)
insert into my_table ( NUM_OPERACIO,TITULS ) values (3,30)
procedure
PROCEDURE solver
IS
arr item_array;
BEGIN
SELECT item( NUM_OPERACIO,TITULS )
BULK COLLECT INTO arr
FROM my_table;
delete from solucion ;
backtra(arr,1,0,30);
END;
What can I do to solve this?
That is a PLS error number. From the documentation:
"PLS-00591: this feature is not supported in client-side programs
Cause: One of the following features was used in a wrong context: pragma AUTONOMOUS_TRANSACTION, dynamic SQL statements, (e.g. EXECUTE IMMEDIATE), and bulk binds. These listed features can only be used in server-side programs but not client-side programs."
Your code uses a bulk-bind, so the error fits. Forms PL/SQL and database PL/SQL are similar but they use different engines, and features supported in both is only a sub-set of all features in either. The solution is to pass the array population into a database procedure and call it from Forms as needed.
Without knowing precisely what problem you're trying to solve, it's harder to give a better answer.
First of all usually I am working with MSSQL. But I have a stored procedure in MSSQL, which I need to use in Oracle now and since I am absolutely new to Oracle I have no idea at all how to do it correct.
I needed to use user defined table types in my MS SQL stored procedure because I am using "logical" tables in my stored procedure, which I also need to pass them to a dynamic sql statement within this procedure (using column names of "physical" tables as variables/parameters).
I've started to add the oracle function in a package I made before for another function. It looks like
TYPE resultRec IS RECORD
(
[result columns]
);
TYPE resultTable IS TABLE OF resultRec;
Function MyFunctionName([A LOT PARAMETERS]) RETURN resultTable PIPELINED;
I also described the layout of the tables (the user defined table types in MSSQL), which I want to use within this function in this package header.
So far so good, but now I don't really know where I have to declare my table variables or user defined table types. I also tried to put them in the package header, but if I am trying to use these tables in the package body, where I am describing my function, Oracle tells met, that the table or view does not exist.
I also tried it to describe the tables within the package body or in the block of my function, which looks like that:
FUNCTION MyFunctionName
(
[MyParameters]
)
RETURN resultTable PIPELINED is rec resultrec;
TYPE tableVariableA IS TABLE OF tableRecA;
TYPE tableVariableB IS TABLE OF tableRecB;
BEGIN
INSERT INTO tableVariableA
SELECT ColumnA, ColumnB FROM physicalTable WHERE[...];
[A LOT MORE TO DO...]
END;
But in this case Oracle also tells me, that it doesn't know the table or view.
I also tried a few more things, but at the end I wasn't able to tell Oracle what table it should use...
I would appreciate every hint, which helps me to understand how oracle works in this case. Thanks a lot!
You can't insert into a collection (e.g. PL/SQL table). You can use the bulk collect syntax to populate the collection:
SELECT ColumnA, ColumnB
BULK COLLECT INTO tableVariableA
FROM physicalTable
WHERE [...];
However, you might want to check this is an appropriate approach, since SQL Server and Oracle differ quite a bit. You can't use PL/SQL tables in plain SQL (at least prior to 12c), even inside your procedure, so you might need a schema-level type rather than a PL/SQL type, but it depends what you will do next. You might not really want a collection at all. Trying to convert T-SQL straight to PL/SQL without understanding the differences could lead you down a wrong path - make sure you understand the actual requirement and then find the best Oracle mechanism for that.
I've been tasked with improving old PL/SQL and Oracle SQL legacy code. In all there are around 7000 lines of code! One aspect of the existing code that really surprises me is the previous coder needlessly created hundreds of lines of code by not writing any procedures or functions - instead the coder essentially repeats the same code throughout.
For example, in the existing code there are literally 40 or more repetitions of the following SQL:
CREATE TABLE tmp_clients
AS
SELECT * FROM live.clients;
CREATE TABLE tmp_customers
AS
SELECT * FROM live.customers;
CREATE TABLE tmp_suppliers
AS
SELECT * FROM live.suppliers WHERE type_id = 1;
and many, many more.....
I'm very new to writing in PL/SQL, though I have recently purchased the excellent book "Oracle PL/SQL programming" by Steven Feuerstein. However, as far as I can tell, I should be able to write a callable procedure such as:
procedure create_temp_table (new_table_nme in varchar(60)
source_table in varchar(60))
IS
s_query varchar2(100);
BEGIN
s_query := 'CREATE TABLE ' + new_table_nme + 'AS SELECT * FROM ' + source_table;
execute immediate s_query;
EXCEPTION
WHEN OTHERS THEN
IF SQLCODE = -955 THEN
NULL;
ELSE
RAISE;
END IF;
END;
I would then simply call the procedure as follows:
create_temp_table('tmp.clients', 'live.clients');
create_temp_table('tmp.customers', 'live.customers');
Is my proposed approach reasonable given the problem as stated?
Are the datatypes in the procedure call reasonable, ie should varchar2(60) be used, or is it possible to force the 'source_table' parameter to be a table name in the schema? What happens if the table name is more than 60 characters?
I want to be able to pass a third non-required parameter in cases where the data has to be restricted in a trivial way, ie to deal with cases "WHERE type_id = 1". How do I modify the procedure to include a parameter that is only used occasionally and how would I modify the rest of the code. I would probably add some sort of IF/ELSE statement to check whether the third parameter was not NULL and then construct the s_query accordingly.
How would I check that the table has actually been created successfully?
I want to trap for two other exceptions, namely
The new table (eg 'tmp.clients') already exists; and
The source table doesn't exist.
Does the EXCEPTION as written handle these cases?
More generally, from where can I obtain the SQL error codes and their meanings?
Any suggested improvements to the code would be gratefully received.
You could get rid of a lot of code (gradually!) by using GLOBAL temporary tables.
Execute immediate is not a bad practice but if there are other options then they should be used. Global temp tables are common where you want to extract and transform data but once processed you don't need it anymore until the next load. Each user can only see the data they insert and no redo logs are generated. You can index the data for faster querying if required.
Something like this
-- Create table
create global temporary table GT_CLIENTS
(
id NUMBER(10) not null,
Client_id NUMBER(10) not null,
modified_by_id NUMBER(10),
transaction_id NUMBER(10),
local_transaction_id VARCHAR2(30) not null,
last_modified_date_tz TIMESTAMP(6) WITH TIME ZONE not null
)
on commit preserve rows;
I recommend the on commit preserve rows option so that you can debug your procedure and see what went into the table.
Usage would be
INSERT INTO GT_CLIENTS
SELECT * FROM live.clients;
If this is the route you want to take to minimize changes, then the error for source table does not exist is -942 which you will want to stop for rather than continuing as your temp table would not have been created. Similarly, just continuing if you get an object already exists error will be problematic as you will not have reloaded it with the new data - the create failed so the table still has the data from the last run. So I would definitely do some more thinking about your exception handler.
That said, I also concur that this is generally not the best way to do things. Creating and dropping objects in a multi-user environment is a disaster in the making, and seems a silly waste of resources when there are more appropriate options available.
i'am facing a problem while trying to make a conception for a school project.and i have two question.
1/
is it possible with oracle to do something like this : https://mariadb.com/kb/en/dynamic-columns/
2/
how can i make a modelisation for that with an MCD (method merise ).
thanks
Quote from your link: "It works by storing a set of columns in a blob and having a small set of functions to manipulate it.". I don't see an obvious reason why you couldn't write something similar for Oracle (or any other relational database).
Alternatively, take a look at EAV, which is a more traditional solution for dynamic columns.
Sorry, I'm not familiar with Merise.
1/ Oracle is not made for creating dynamic columns, but you can do it by using PL/SQL functions (but not while querying with SQL):
create or replace procedure add_table_column(table_name varchar2, column_name varchar2, column_type varchar2)
is
v_script varchar2(4000);
begin
v_script := 'alter table '||table_name||' add '||column_name||' '||column_type;
execute immediate v_script;
end;
/
You can call it this way:
begin
add_table_column('toto','test','number');
end;
/
2/ Merise method is not made for "dynamic objects" as you must begin with a complete data dictionary.
How is your object dynamic, and why do you have to add columns?
You can always get a solution to work by using "regular" tables and relationships.
It sounds like you should start by analyzing the technical implementation in mind. MERISE says to analyze your data model first and start to think about technical solutions after.
There have been a couple of hints that seem to have gotten me close here, but with some unique issues, I'm hoping this question is distinguishing enough to merit its own posting.
For starters here's what I have. I have an Oracle procedure that returns a standard REF CURSOR, and this REF CURSOR is passed back to my application. The REF CURSOR is a list of lookup IDs.
I then want to take this list and bring it to another data store and use it in a select statement. It will absolutely be possible to accomplish this by looping through the REF CURSOR, but I'm hoping to avoid that. I would much rather be able to write a SELECT...WHERE lookup_id IN result_ref_cursor OR SELECT...WHERE EXISTS...
First is this possible or should I just try a less than elegant solution? If it is possible, any hints as to where I should get started looking?
I'm relatively new to Oracle, but fairly experienced in RDBMs in general, so feel free to just through some links at me and I can study up. Much appreciated
Why kurosch didn't put his response as an "answer" I'll have no idea.
So, what you do is define a SQL type which describes one row of the output of the ref cursor, and also a SQL type which is a table of the previous. Then, you'll create a pipelined function which returns the rows returned by the ref cursor. This function can then be used in a standard SQL. I'm borrowing from Ask Tom on this one.
create or replace type myLookupId as object ( id int)
/
create or replace type myLookupIdTable as table of myLookupId
/
create or replace function f return myLookupIdTable PIPELINED is
l_data myLookupId;
l_id number;
p_cursor SYS_REFCURSOR;
begin
p_cursor := function_returning_ref_cursor();
loop
fetch p_cursor into l_id;
exit when p_cursor%notfound;
l_data := myLookupId( l_id );
pipe row (l_data);
end loop;
return;
end;
/
And now a sample query...
SELECT *
FROM SOME_TABLE
WHERE lookup_id in (SELECT ID FROM table(f));
Sorry if the code isn't exactly right, I don't have the DB to test right now.
There are several directions you could go with this, but I did a search on the specific solution you want and it seems like no-one has done it often enough to show up there. What you can do is search the oracle metalink - that is usually really good at finding obscure answers. (Though you do need a service agreement - just found out that mine expired :( )
Other possible solutions:
Create a link between the data stores so that you can do the select in the plsql directly
Create a function in Java that loops through it for you to create the string for the query. This will look a little more pretty at least.
Otherwise, REF CURSOR's need to go back and forth - I don't know how you can pipe the results of the REF CURSOR in one connection to the query in another without looping through it.