How to delete multiple rows using shuttle page item in Oracle Apex? - oracle

My requirement is that users must be able to select from a shuttle page item the employee numbers that they need to delete from a table. In the back end I have a plsql code that is supposed to delete the selected employee numbers as follows:
BEGIN
delete from employees where empno in (:P7_EMPLOYEE_NUMBER);
END;
Additionally I will have more logic in the code to do other stuff, however I am not able to delete multiple rows, if I select 1 employee number in the shuttle item, I am able to delete the record successfully, when I try to delete more than one record I keep getting the following error:
Ajax call returned server error ORA-01722: invalid number for Execute Server-Side Code
I changed the code to:
BEGIN
delete from employees where empno in (to_number(:P7_EMPLOYEE_NUMBER));
END;
and I keep getting the same error message.
How can I make this work?

The API APEX_STRING has a number of utility functions to deal with multi-value page items (select lists, checkbox, shuttles). To convert a colon separated list to an array, use APEX_STRING.SPLIT.
DELETE
FROM
employees
WHERE empno IN
(SELECT column_value
FROM table(apex_string.split(: P7_EMPLOYEE_NUMBER,':'))
);

A shuttle item contains colon-separated values, which means that you have to split it to rows, e.g.
delete from employees
where empno in (select regexp_substr(:P7_EMPLOYEE_NUMBER, '[^:]+', 1, level)
from dual
connect by level <= regexp_count(:P7_EMPLOYEE_NUMBER, ':') + 1
);

The APEX engine will always submit multi-values items as a single colon-delimited string, for example: 1:2:3:4
You need to split the string into multiple values so that you can process them.
There are multiple ways to do this:
Using an the APEX_STRING.SPLIT or the APEX_STRING.SPLIT_NUMBERS API in a subquery
delete from employees
where empno in (select column_value
from apex_string.split_numbers(:P7_EMPLOYEE_NUMBER, ':'));
Using the APEX_STRING API with the MEMBER OF function
delete from employees
where empno member of apex_string.split_numbers(:P7_EMPLOYEE_NUMBER, ':');
Note that the member of needs to have the same type. In this case empno is a number so you must use the split_numbers API.
Using a regular expression to split the values
delete from employees
where empno in (select regexp_substr(:P7_EMPLOYEE_NUMBER, '[^:]+', 1, level)
from dual
connect by level <= regexp_count(:P7_EMPLOYEE_NUMBER, ':') + 1
);
I prefer using option 2 as it's less code and easier to read.

Related

Oracle access varray elements in SQL

I'm playing around with array support in Oracle and hit a roadblock regarding array access within a SQL query. I'm using the following schema:
create type smallintarray as varray(10) of number(3,0);
create table tbl (
id number(19,0) not null,
the_array smallintarray,
primary key (id)
);
What I would like to do is get the id and the first element i.e. at index 1 of the array. In PostgreSQL I could write select id, the_array[1] from tbl t but I don't see how I could do that with Oracle. I read that array access by index is only possible in PL/SQL, which would be fine if I could return a "decorated cursor" to achieve the same result through JDBC, but I don't know if that's possible.
DECLARE
c1 SYS_REFCURSOR;
varr smallintarray2;
BEGIN
OPEN c1 FOR SELECT t.id, t.THE_ARRAY from tbl t;
-- SELECT t.THE_ARRAY INTO varr FROM table_with_enum_arrays2 t;
-- return a "decorated cursor" with varr(1) at select item position 1
dbms_sql.return_result(c1);
END;
You can do this in plain SQL; it's not pretty, but it does work. You would prefer that Oracle had syntax to hide this from the programmer (and perhaps it does, at least in the most recent versions; I am still stuck at 12.2).
select t.id, q.array_element
from tbl t cross apply
( select column_value as array_element,
rownum as ord
from table(the_array)
) q
where ord = 1
;
EDIT If order of generating the elements through the table operator is a concern, you could do something like this (in Oracle 12.1 and higher; otherwise the function can't be part of the query itself, but it can be defined on its own):
with
function select_element(arr smallintarray, i integer)
return number
as
begin
return arr(i);
end;
select id, select_element(the_array, 1) as the_array_1
from tbl
/
First of all, please don't do that on production. Use tables instead of storing arrays within a table.
Answer to your question is to use column as a table source
SELECT t.id, ta.*
from tbl t,
table(t.THE_ARRAY) ta
order by column_value
-- offset 1 row -- in case if sometime you'll need to skip a row
fetch first 1 row only;
UPD: as for ordering the array I can only say playing with 2asc/desc" parameters provided me with results I've expected - it has been ordered ascending or descending.
UPD2: found a cool link to description of performance issues might happen

How to create and use a multi-select list in APEX ORACLE?

I have a table called Employees with Employee_id and Employee_Name columns. Now i want to create a page with Checkbox in-front of every Employee Name, select the ones that are needed, store them into a temporary table and use them for further operations. The problem i am facing is to how to create that multi select list and store the select values in thee table. Is there an Item for multi select? If not, how should i do it?
There's the Shuttle item. On the left side, you'd display list of all employees. Item buttons allow you to move all (or only some of them) to the right side of the item. Once you submit the page, list of employee IDs is stored into a table column in a form of colon-separated values, for example
6547:8879:5587:9987
This is a simple way of doing that. However, once you have to actually do something with those values, you have to split them to rows. Not a problem, though. Here's a query:
SQL> with emps (shuttle_item) as
2 (select '6547:8879:5587:9987' from dual)
3 select regexp_substr(shuttle_item, '[^:]+', 1, level) one_item
4 from emps
5 connect by level <= regexp_count(shuttle_item, ':') + 1;
ONE_ITEM
---------------------------------------------------------------------
6547
8879
5587
9987
SQL>
Or, you could create a tabular form which also displays all employees and has checkboxes at the beginning of every line. You'd then create a process which - in a loop - stores selected values into a temporary table you mentioned. For example:
-- F01 = row selector. If you check 1st and 3rd row, f01.count = 2 (2 rows checked)
-- f01(1) = 1 (row #1), f01(2) = 3 (row #3)
-- F02 = EMP_ID. f02(1) = EMP_ID that belongs to employee in 1st row,
-- f02(3) = EMP_ID that belongs to emplyee in 3rd row
declare
l_id number;
begin
for j in 1 .. apex_application.g_f01.count
loop
l_id := apex_application.g_f02(apex_application.g_f01(j));
insert into temp_table (emp_id) values (l_id);
end loop;
end;
There is an option for creating multi select list in oracle apex 5.1.
Create a pageItem of type: 'select list'.
Make the 'Allow multi
selection' to 'Yes'.
Write the SQL query for your select list under
the 'List of Values' attribute.
Then the select list will be
displayed based on our query.
Query format is:
select [displayValue],
[returnValue]
from ...
where ...
order by ...
Now once you select multiple value from select list(using ctrl+click), these are stored as ':' separated values in the select list page item.
I've created a video some times ago that covers your problem. It's a step by step tutorial how to create checkboxes and process them.
Video is available here:
https://www.youtube.com/watch?v=T-LXRMWQbPk
Regards
If the list is too big, I recommend to use the Popup LOV item with the Multiple Values switch activated instead the Select list or the Shuttle, because it has an internal search field for the objects list, doing way easier for the user to find the target values. Also, just as the Select List or Shuttle item, you can set a Separator character for the selected fields.

Transfer values between pages in Oracle APEX

I am working on Oracle APEX 5 and wanted to transfer values added into List manager (in page 2) to display them on Page 3 as read-only. How can we do that?
What type of item to choose to display values in page 3? and how to get these values from list manager?
please help.Thanks in advance.
The List Manager item type can hold multiple values, which are delimited by a colon e.g. '7782:7902:7788:7698'. If you pass this item value to a hidden item in the target page then you can call apex_string.split to convert it to an array of values, which you can then process as you wish. For example, if the values are EMPNOs and you want to display all the names in a display only item you can write code like:
declare
empno_array wwv_flow_t_varchar2;
begin
empno_array := apex_string.split (:P3_HIDDEN_ITEM, ':');
select listagg (ename, ', ') within group (order by ename)
into :P3_DISPLAY_ITEM
from emp
where empno in (select column_value
from table(empno_array));
end;

PLSQL - Parameter cursor with different return

I know the title is saying nothing... but the argument is a little "complex" to explain in a single row.
All the code i'm writing is just an example, my current code is from other table etc, but the behaviour is the same.
i have defined a cursor like this:
CURSOR emp_cur (l_type)
IS
with emp_general AS (select *
from emp
where type = l_type),
emp_active AS (select *
from emp_geral
where status = ACTIVE_STATUS),
emp_inactive AS (select *
from emp_general
where status = INACTIVE_STATUS)
select distinct name, department
from emp_active
minus
select distinct name, department
from emp_inactive;
This cursor take a parameter for filter emp type and make a minus to fetch ACTIVE - INACTIVE emp.
This cursor return name and department.
Now have to declare different cursor with different "select" statemant, for example:
select location
from emp_active
select location
from emp_active
I would like to dont duplicate my cursor just to change the select. There is a way to do this and avoid code duplication (withuout using DynamicSQL - Difficult to debug in production enviroment)?
You could create two Global temporary tables explicitly once(not on the fly):
emp_active_gtt
emp_inactive_gtt
Such that, each temp table will have the entire result set of active and inactive records respectively.
For example, in the code you would do:
insert into emp_active_gtt
select *
from ....
where status ='ACTIVE'
Similarly, for inactive records:
insert into emp_inactive_gtt
select *
from ....
where status ='INACTIVE'
You could now use the two tables in the scope of the session anywhere to get the required rows.
Read more about GTT in the documentation here https://docs.oracle.com/database/121/SQLRF/statements_7002.htm#i2153132

PL/SQL procedure - too many values

I'm sure this is something simple, but I'm really new to PL/SQL and this has me stuck.
I've written a simple stored procedure to return a few values about a customer. Right off the bat, the %rowtype's are not coming up as reserved keywords but the compiler isn't flagging those as errors.
It is, however, ignoring the entire SQL statement flagging the line FROM demo_customers as too many values. Even if I try reducing it to only select one column it still gives me the same error.
create or replace
PROCEDURE GETCUSTOMER
(
arg_customerID demo_customers.customer_id%type,
returnRec OUT demo_customers%rowtype
)
AS
BEGIN
SELECT customer_id, cust_first_name, cust_last_name, cust_email
INTO returnRec
FROM demo_customers
WHERE customer_id = arg_customerID ;
END GETCUSTOMER;
If you want to select into a %ROWTYPE record, you'll want to do a SELECT * rather than selecting individual columns
create or replace
PROCEDURE GETCUSTOMER
(
arg_customerID demo_customers.customer_id%type,
returnRec OUT demo_customers%rowtype
)
AS
BEGIN
SELECT *
INTO returnRec
FROM demo_customers
WHERE customer_id = arg_customerID ;
END GETCUSTOMER;
If you select 4 columns explicitly, Oracle expects you to have 4 variables to select those values into.

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