Oracle Update and select in a single query - oracle

I'm working with a vendor's database, and I need to increment a value and return it. I have the right command, it updates the table, but the output in oracle developer just says "PL/SQL procedure successfully completed." How do I return NewReceiptNumber?
DECLARE
NewReceiptNumber int;
BEGIN
UPDATE SYSCODES
SET (VAR_VALUE) = VAR_VALUE+1
WHERE VAR_NAME='LAST_RCPT'
RETURNING VAR_VALUE INTO NewReceiptNumber;
END;

You are just depicting an anonymous block there, to VIEW the value of NewReceiptNumber in that code you'll have to use:
dbms_output.put_line(NewReceiptNumber).
as in:
DECLARE
NewReceiptNumber int;
BEGIN
UPDATE SYSCODES
SET (VAR_VALUE) = VAR_VALUE+1
WHERE VAR_NAME='LAST_RCPT'
RETURNING VAR_VALUE INTO NewReceiptNumber;
dbms_output.put_line(NewReceiptNumber);
END;
But if your intention is to actually return this value to another procedure or a call from your front-end, you'll have to declare a stored procedure and within that declaration indicate your output parameter, something like:
CREATE OR REPLACE PROCEDURE my_proc(newreceiptnumber out INT) AS
BEGIN
UPDATE syscodes
SET (var_value) = var_value+1
WHERE var_name='LAST_RCPT'
RETURNING var_value INTO newreceiptnumber;
END my_proc;
And of course it'll be a more robust solution if you send your updated values as parameters as well, this is just the minimal approach.

Related

Why in Oracle forms (based on procedure) query does not return any values?

I have made a data block in oracle forms using Data Block Wizzard, however query does not populate the form. Even though cursor returns values and enters the loop in query procedure:
Here is the code of query procedure:
PROCEDURE PD_PDT_SCHEDULE_TYPES_QUERY(par_pd_pdt_schedule_types_tbl IN OUT gt_pd_pdt_schedule_types_tbl) IS
lc_err_msg VARCHAR2(2000);
lc_add_rec VARCHAR2(1);
lc_search_ok VARCHAR2(1);
CURSOR c_pd_pdt_schedule_types IS
SELECT pst_code,
pst_prty,
pst_mnemo,
pst_name,
pst_crt_mandatory,
pst_pdt_mnemo,
pst_type,
pst_purpose,
pst_purpose_det,
pst_ref_mnemo,
pst_hidden,
pst_ref_show,
pst_payment_show
FROM s_pd_pdt_schedule_types where pst_pdt_mnemo = 'SOME_PRODUCT';
ln_idx NUMBER := 1;
BEGIN
FOR i IN c_pd_pdt_schedule_types
LOOP
par_pd_pdt_schedule_types_tbl(ln_idx) := i;
ln_idx := ln_idx + 1;
END LOOP;
EXCEPTION
WHEN OTHERS THEN
lc_err_msg := 'FRL_184.PD_PDT_SCHEDULE_TYPES_QUERY error: ' || SQLERRM;
RAISE_APPLICATION_ERROR(-20555, SUBSTR(lc_err_msg, 1, 2000));
END PD_PDT_SCHEDULE_TYPES_QUERY;
Here is the code of form trigger Query-Procedure:
DECLARE
bk_data FRL_184.GT_PD_PDT_SCHEDULE_TYPES_TBL;
BEGIN
frl_184.PD_PDT_SCHEDULE_TYPES_QUERY(bk_data);
PLSQL_TABLE.POPULATE_BLOCK(bk_data, 'S_PD_PDT_SCHEDULE_TYPES');
END;
First of all, make sure that PD_PDT_SCHEDULE_TYPES_QUERY actually does something - test it in SQL*Plus (or SQL Developer or any other tool you use).
QUERY-PROCEDURE trigger is created by the Wizard; it is as is, there's nothing you should do about it. Forms says that you shouldn't modify it anyway.
In order to make it work, you should edit data block's properties - go to the Palette, navigate to the "Database" section and open Query data source columns - in there, you should enter ALL columns returned by the procedure, i.e. pst_code, pst_prty, etc., along with their datatypes, length, precision ... depending on the datatype itself.
Also, modify Query data source arguments property. As your procedure doesn't accept any IN parameters, it would be just one argument (TABLE type, write its name, mode is IN OUT). If you passed some parameters to the procedure, you'd put them in here as well.
That would be it, I think.

A syntax for custom lazy-evaluation/short-circuiting of function parameters

Oracle defines several structures that make use of what looks like lazy evaluation but what's actually short-circuiting.
For example:
x := case when 1 = 2 then count_all_prime_numbers_below(100000000)
else 2*2
end;
The function count_all(...) will never be called.
However, what I'm more interested in is the syntax that looks like regular function call:
x := coalesce(null, 42, hundreth_digit_of_pi());
Hundreth_digit_of_pi() will not be called since coalesce is not a regular function, but a syntax sugar that looks like one - for regular ones parameters get evaluated when the function is called.
The question is:
is it possible do define in plsql a custom procedure/function that would behave in the same way?
If you're not convinced I'll give an example when that could be useful:
We use ''framework'' for logging.
To trace something you call a procedure:
trace_something('A text to be saved somewhere');
Trace_something is 'pragma autonomous transaction' procedure that does the following steps:
1. See, if any tracing methods (for example file / db table) are enabled
2. For every enabled method use that method to save parameter somewhere.
3. If it was saved to DB, commit.
A problem occurs when building the actual string to be traced might take noticable amount of time, and we wouldn't want to have to spend it, if tracing isn't even enabled in the first place.
The objective would be, in pseudocode:
procedure lazily_trace_something(some_text lazily_eval_type) {
if do_i_have_to_trace() = TRUE then
trace_something(evaluate(some_text));
else
NULL; -- in which case, some_text doesn't get evaluated
end if;
}
/*
*/
lazily_trace_something(first_50_paragraphs_of_lorem_ipsum(a_rowtype_variable));
Is it possible to be done in plsql?
Lazy evaluation can be (partially) implemented using ref cursors, conditional compilation, or execute immediate. The ANYDATA type can be used to pass generic data.
Ref Cursor
Ref cursors can be opened with a static SQL statement, passed as arguments, and will not execute until needed.
While this literally answers your question about lazy evaluation I'm not sure if it's truly practical. This isn't the intended use of ref cursors. And it may not be convenient to have to add SQL to everything.
First, to prove that the slow function is running, create a function that simply sleeps for a few seconds:
grant execute on sys.dbms_lock to <your_user>;
create or replace function sleep(seconds number) return number is
begin
dbms_lock.sleep(seconds);
return 1;
end;
/
Create a function to determine whether evaltuation is necessary:
create or replace function do_i_have_to_trace return boolean is
begin
return true;
end;
/
This function may perform the work by executing the SQL statement. The SQL statement must return something, even though you may not want a return value.
create or replace procedure trace_something(p_cursor sys_refcursor) is
v_dummy varchar2(1);
begin
if do_i_have_to_trace then
fetch p_cursor into v_dummy;
end if;
end;
/
Now create the procedure that will always call trace but will not necessarily spend time evaluating the arguments.
create or replace procedure lazily_trace_something(some_number in number) is
v_cursor sys_refcursor;
begin
open v_cursor for select sleep(some_number) from dual;
trace_something(v_cursor);
end;
/
By default it's doing the work and is slow:
--Takes 2 seconds to run:
begin
lazily_trace_something(2);
end;
/
But when you change DO_I_HAVE_TO_TRACE to return false the procedure is fast, even though it's passing a slow argument.
create or replace function do_i_have_to_trace return boolean is
begin
return false;
end;
/
--Runs in 0 seconds.
begin
lazily_trace_something(2);
end;
/
Other Options
Conditional compilation is more traditionally used to enable or disable instrumentation. For example:
create or replace package constants is
c_is_trace_enabled constant boolean := false;
end;
/
declare
v_dummy number;
begin
$if constants.c_is_trace_enabled $then
v_dummy := sleep(1);
This line of code does not even need to be valid!
(Until you change the constant anyway)
$else
null;
$end
end;
/
You may also want to re-consider dynamic SQL. Programming style and some syntactic sugar can make a big difference here. In short, the alternative quote syntax and simple templates can make dynamic SQL much more readable. For more details see my post here.
Passing Generic Data
The ANY types can be use to store and pass any imaginable data type. Unfortunately there's no native data type for each row type. You'll need to create a TYPE for each table. Those custom types are very simple so that step can be automated if necessary.
create table some_table(a number, b number);
create or replace type some_table_type is object(a number, b number);
declare
a_rowtype_variable some_table_type;
v_anydata anydata;
v_cursor sys_refcursor;
begin
a_rowtype_variable := some_table_type(1,2);
v_anydata := anydata.ConvertObject(a_rowtype_variable);
open v_cursor for select v_anydata from dual;
trace_something(v_cursor);
end;
/

How to use One procedure output variable data into another procedure

I have one requirement in which I have to design two procedure.First procedure will generate one output variable value and then second procedure will use to do its task. I am giving same kind of scenario in below code
create procedure existingProc(
begin
insert statementprogramming statement
);
create procedure MyProc(
begin
call existingProc();
-- Exsisting procedure return some value
-- and this value is used in MyProc
commit;
);
In the above code existingProc is already there in the system and I can not change it. IN the procedure transaction is begin but not committed. This procedure generate one value as Output param and MyProc will used this value.
I want that after executing the existingProc, MyProc procedure should get the value, but it is not happening and it is giving null.
what should i do here, Please help me. I can not share the code that why giving scenario.
Does this help clarify how to use the output parameters from one procedure in another procedure?
create procedure ExistingProc(output1 out number) is
begin
insert into someTable values ('some values')
RETURNING someCol INTO output1;
end;
create procedure MyProc(args ....) is
Result1 number; --output from existingProc
begin
ExistingProc(result1);
-- Use Result1 as needed
Update stuff ...
where id = Resutl1;
commit;
end;

How to retrieve values post-execution of PL/SQL stored procedure?

Im very new to oracle database stuff. There is a PL/SQL proceedure which someone else wrote and is stored on the database I am accessing. I want my program to execute it and retrieve the result. Execution is working. I cannot retrieve the result however. Obviously I am not doing it right, but I cannot find the right way in the documentation.
Here is the gist of the stored procedure (with extraneous lines removed)
procedure ISDRAWINGVALID(DWGNO_IN in VARCHAR2) is
valid BOOLEAN;
begin
-- do some stuff to see if the drawing is valid
IF <some stuff> THEN
valid := TRUE;
ELSE
valid := FALSE;
END IF;
END ISDRAWINGVALID;
My program issues the following commands to the database to execute and retrieve the return.
BEGIN ISDRAWINGVALID( <drawingnumber> ); END;
SELECT ISDRAWINGVALID.valid FROM DUAL;
The first line works fine, the proceedure executes and has the desired effect.
The second line returns an error, invalid identifier "ISDRAWINGVALID.valid"
Clearly i am not using the right way to retrieve the value. Can someone please clue me in?
thanks
As you present the problem, there is no way to get the result.
If you can get the procedure as a function instead, you can call it directly in the select statement.
Otherwise you would have to take a long detour to solve it, involving a result table or a pl/sql package with a result function and a package variable.
The procedure you have there has been made to be called from other pl/sql code - not in a select query.
EDIT
I think I might be wrong after all.
In Java you can create a prepared statement with a call, and pick up the return value directly as a result-set.
Check this out and come back with the result: http://archive.oreilly.com/pub/a/onjava/2003/08/13/stored_procedures.html?page=2
Sorry if you are not using Java, I was not able to see what you are using.
Use a function and return a NUMBER to be used in SQL:
CREATE OR REPLACE
FUNCTION ISDRAWINGVALID(DWGNO_IN in VARCHAR2) RETURN NUMBER
IS
valid NUMBER;
BEGIN
IF <some stuff> THEN
valid := 1;
ELSE
valid := 0;
END IF;
RETURN valid;
END ISDRAWINGVALID;
Use from PL/SQL:
DECLARE
valid NUMBER;
BEGIN
valid := ISDRAWINGVALID( <drawingnumber> );
END;
/
Use from SQL:
SELECT ISDRAWINGVALID( <drawingnumber> ) FROM DUAL;

How to declare / assign a variable to a cursor type in PL/SQL procedure

I have two cursors declared in a stored procedure (inside a package).
procedure RECONCILE_CC_TRX (p_to_date in date,
p_nz_flag in varchar2,
p_Reconcile_Header_ID out NUMBER
) is
CURSOR LOADED_TRXS_AU IS
SELECT
CC_REC_LOAD_TRX_ID,
CC_REC_LOAD_HEADER_ID,
....
CURSOR LOADED_TRXS_NZ IS
SELECT
CC_REC_LOAD_TRX_ID,
CC_REC_LOAD_HEADER_ID,
The only difference between the two cursors is the where clause.
What I want to do, is open one of those cursors based on the p_nz_flag passed in above. ie:
IF NVL(p_nz_flag, 'F') = 'F' THEN
v_load_trx_cursor := LOADED_TRXS_AU;
ELSE
v_load_trx_cursor := LOADED_TRXS_NZ;
END IF;
FOR bitem IN v_load_trx_cursor LOOP
...
My initial thinking was to declare a variable and assign it the appropriate cursor, however, I can't get the procedure to compile with this. eg, I have tried:
v_load_trx_cursor sys_refcursor;
but I get a compilation error when assigning v_load_trx_cursor of "PLS-00382: Expression is of wrong type". If I change my declaration to:
v_load_trx_cursor cursor;
I get compilation error at the declaration point stating "PLS-00201: Identifier 'Cursor' must be declared.
Is it possible to do what I want to do? At the end of the day, I just want to iterate the appropriate cursor based on the p_nz_flag parameter passed in.
Thanks
It looks like you want to use only one cursor in your code, based on the value of p_nz_flag
In this case, believe it will be better to make the where clause dynamically in your code and then use refcursor to return the data of the query.
Something like given in Example 7-4 on this link Dynamic Query with Refcursor
Hope it Helps
Vishad
Hi if your whole work for doing this procedure is just to populate the appropriate cursor i think this code may help you.
CREATE OR REPLACE PROCEDURE av_nst_cursor(
flag_in IN VARCHAR2,
av_cur OUT sys_refcursor)
AS
BEGIN
IF flag_in = 'Y' THEN
OPEN av_cur FOR SELECT Query;
ELSE
OPEN av_cur FOR SELECT query;
END IF;
END;

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