I have a sequence named WCOMP_SEQ in oracle to generate auto increment column ON WCOMP table. When I insert a row to WCOMP table in SQLPlus, the row inserted and I can get the auto increment value using
SELECT WCOMP_SEQ.currval FROM dual
But when I ran insert a row using Database Class in CodeIgniter, the row inserted but when I ran the query above to get auto increment value I got Exception:
Exception: Undefined Index currval in E:...
How to fix this?
There is a way to get the value automatically assigned to a column: it is the RETURNING clause.
So, here is my sequence:
SQL> select emp_seq.currval from dual
2 /
CURRVAL
----------
8140
SQL>
I'm going to use it in an INSERT statement:
SQL> var seqval number
SQL> insert into emp
2 (empno, ename, deptno, sal, job)
3 values
4 (emp_seq.nextval, 'JELLEMA', 50, 4575, 'PAINTER')
5 returning empno into :seqval
6 /
1 row created.
SQL>
I returned the EMPNO into a SQL*Plus variable which I can print, and it has the same value as CURRVAL:
SQL> print :seqval
SEQVAL
----------
8141
SQL> select emp_seq.currval from dual
2 /
CURRVAL
----------
8141
SQL>
Your next question is, "does CodeIgniter support the RETURNING sysntax?" I have no idea, but I suspect it does not. Most non-Oracle frameworks don't.
There is always the option to wrap the INSERT statement in a stored procedure, but that's an architectural decision whoch many people dislike.
You can not fetch the SEQUENCE current value without issuing NEXTVAL (see here). So, if you do not want to increment the sequence value (by using NEXTVAL), you should instead query USER_SEQUENCES.
Something like this:
select Sequence_Name
, Last_Number
from user_sequences
where sequence_name = 'WCOMP_SEQ'
/
SEQUENCE_NAME LAST_NUMBER
------------- -----------
WCOMP_SEQ 20
Hope this helps.
In order to get currval on the sequence you will need to have at least one reference to the corresponding nextval for the sequence in the current user session. This is what causes it to set the currval value which would belong to the session.
If you are using it outside, it defeats the purpose which value could it return if there were other sessions active.
Related
i created a table but i forgot to add a sequence to one of the PK, its a sequence on a form page, i just cant find anything about it, is it possible or do i have to do the form all over again.
i tried to replace the PK but it doesnt give me the option to add the sequence when creating a new one.
i searched everywhere and asked the support in chat (didn't really help since its not their job).
all i could find was this and this.
I'd suggest you to skip Apex in this matter and do the following: presume this is your table:
SQL> create table test
2 (id number constraint pk_test primary key,
3 name varchar2(20)
4 );
Table created.
This is the sequence:
SQL> create sequence myseq;
Sequence created.
As you forgot to specify PK source while creating Apex Form page, never mind - let the database handle it. How? Create a BEFORE INSERT trigger:
SQL> create or replace trigger trg_bi_test
2 before insert on test
3 for each row
4 when (new.id is null)
5 begin
6 :new.id := myseq.nextval;
7 end trg_bi_test;
8 /
Trigger created.
Let's test it: I'm inserting only the NAME (which is what your Apex Form will be doing):
SQL> insert into test (name) values ('Littlefoot');
1 row created.
What is table's contents?
SQL> select * from test;
ID NAME
---------- --------------------
1 Littlefoot
SQL>
See? Trigger automatically inserted ID (primary key) column value.
If it were an Interactive Grid (which lets you insert several records at a time):
SQL> insert into test (name)
2 select 'Bigfoot' from dual union all
3 select 'FAD' from dual;
2 rows created.
SQL> select * from test;
ID NAME
---------- --------------------
1 Littlefoot
2 Bigfoot
3 FAD
SQL>
Works just fine.
And what's another benefit: you don't have to modify Apex application at all.
so i'm trying to create a trigger, but always have an error that says
Trigger LOG_SALARY compiled
LINE/COL ERROR
--------- ------------------------------------------------------------- 2/2 PL/SQL: SQL Statement ignored 3/9 PL/SQL: ORA-00934: group
function is not allowed here Errors: check compiler log
Error(2,2):PL/SQL: SQL Statement ignored
Error(3,9):PL/SQL:ORA-00934:group function is not allowed here
this is my code
'''alter table department add AVG_SALARY number(10);
alter table department add MAX_SALARY number(10);
alter table department add MIN_SALARY number(10);
insert into department (AVG_SALARY, MAX_SALARY, MIN_SALARY) values (AVG(salary), MAX(salary) ,MIN(salary));
create or replace TRIGGER log_salary
after update of salary on employee
for each row
begin
insert into DEPARTMENT(AVG_SALARY, MAX_SALARY, MIN_SALARY)
values(AVG(SALARY),MAX(SALARY),MIN(SALARY));
end;
update department
set salary = salary + 100.0
where SSN =888665555;
select * from DEPARTMENT;'''
could you tell me what is wrong with my code?
thankyou in advance!
You are inserting new rows into the department table. I think you want to update them. The logic looks like this:
create or replace TRIGGER log_salary
after update of salary on employee
for each row
begin
update department
set (AVG_SALARY, MAX_SALARY, MIN_SALARY) =
(select AVG(SALARY), MAX(SALARY), MIN(SALARY)
from employee
where e.department_id = :new.department_id
end;
This however will probably generate a mutating table error. Addressing that is really difficult. For instance, consider this:
emp_id dept_id salary
1 1 10
2 1 10
3 1 5
If you change emp_id's salary to 20, then the max is 20. But if you change the salary to 5, then the max remains 10.
I would suggest that you just use a view to calculate the values on-the-fly.
Consider a view branch_cust defined as follows:
Create view branch_cust as
select
branch_name,
customer_name
from depositor, account
where depositor.account_number = account.account_number
suppose that a view is materialized; that is the view is computed and stored. Write a trigger to maintain the view, that is, to keep it up-to-date on insertions to and deletions from depositor or account. Do not bother about updates.
I tried doing an insert trigger on depositor using referencing new table as
But it is throwing errors.
This is the code.
create or replace trigger insert_dep
after insert on depositor REFERENCING NEW TABLE as inserted
FOR EACH ROW BEGIN
insert into branch_cust select branchname, cusname
from inserted, account
where inserted.account = account.acc; end;
Question is not clear, is branch_cust a table or view or materialized view ??
I will try to answer for all 3 cases :
branch_cust is view : and looking at the given DDL by you its a complex view, which means DMLs on it will fail. Also, since you are inserting into branch_cust(which is formed from table depositor) using a trigger which is also upon depositor you will get mutating error even if you make the view Simple.
so, this scenario will never work out.
branch_cust is materialized view : you cannot perform insert into a materialized view. so, trigger will fail
branch_cust is table : this can be achieved if you want to keep a separate copy of depositor data joined by account. but i suggest not to do it.
suppose that a view is materialized
Then it makes no sense in inserting into it, as those changes would be lost anyway at the first refresh.
Therefore, as it seems that you wanted to refresh it as soon as changes are made in its source table, set it to refresh on commit. Here's an example:
SQL> create materialized view mv_emp
2 refresh complete
3 on commit
4 as
5 select deptno, sum(sal) sumsal
6 From emp
7 group by deptno;
Materialized view created.
SQL> select * from mv_emp order by deptno;
DEPTNO SUMSAL
---------- ----------
10 13750
20 10995
30 9400
SQL> update emp set sal = sal + 1 where deptno = 10;
3 rows updated.
SQL> commit;
Commit complete.
SQL> select * from mv_emp order by deptno;
DEPTNO SUMSAL
---------- ----------
10 13753 --> new value for DEPTNO = 10
20 10995
30 9400
SQL>
How to increment the value of the unique constraint column value in ORACLE, in the select statement.
For example, in a table 'BILLING_TABLE' - column BLNG_Sk is the unique key (Autoincremented).
So while inserting a new record into the BILLING_TABLE, for the column BLNG_SK we need to give the value (Which is the increment by 1 from the present max value.)
For example, if BLNG_SK max value is 12321.
new record should be 12322.
how to achieve this in Oracle?
Oracle has a SEQUENCE object which provides the functionality you require.
You create one using the CREATE SEQUENCE SQL statement.
The Oracle documentation provides all the required information and the documentation is available via Oracle's Web site.
Assuming you are on Oracle 12.1 or later, define it as an identity column and do not pass any value when inserting:
create table testtable
( test_id number generated always as identity
constraint testtable_pk primary key
, othercol varchar2(10) );
insert into testtable (othercol) values ('Demo');
select * from testtable;
TEST_ID OTHERCOL
---------- ----------
1 Demo
insert into testtable (othercol) values ('Demo #2');
select * from testtable;
TEST_ID OTHERCOL
---------- ----------
1 Demo
2 Demo #2
Try creating a sequence and a trigger. This is the case when you provide the value manually.
CREATE SEQUENCE dept_seq START WITH 12322;
Trigger definition:
CREATE OR REPLACE TRIGGER dept_bir
BEFORE INSERT ON BILLING_TABLE
FOR EACH ROW
BEGIN
SELECT dept_seq.NEXTVAL
INTO :new.id
FROM dual;
END;
/
I'm using Oracle on database server, from an XP client, using VB6 and ADO. In one transaction, I'm inserting one record into a parent table, which has a trigger and sequence to create a unique recordid, then that recordid is used for the relationship to a child table for a variable number of inserts to the child table. For performance, this is being sent in one execute command from my client app. For instance (simplified example):
declare Recordid int;
begin
insert into ParentTable (_field list_) Values (_data list_);
Select ParentTableSequence.currVal into Recordid from dual;
insert into ChildTable (RecordID, _field list_) Values (Recordid, _data list_);
insert into ChildTable (RecordID, _field list_) Values (Recordid, _data list_);
... multiple, variable number of additional ChildTable inserts
commit;
end;
This is working fine. My question is: I also need to return to the client the Recordid that was created for the inserts. On SQL Server, I can add something like a select to Scope_Identity() after the commit to return a recordset to the client with the unique id.
But how can I do something similar for Oracle (doesn't have to be a recordset, I just need that long integer value)? I've tried a number of things based on results from searching the 'net, but have failed in finding a solution.
These two lines can be compressed into a single statement:
-- insert into ParentTable (field list) Values (data list);
-- Select ParentTableSequence.currVal into Recordid from dual;
insert into ParentTable (field list) Values (data list)
returning ParentTable.ID into Recordid;
If you want to pass the ID back to the calling program you will need to define your program as a stored procedure or function, returning Recordid as an OUT parameter or a RETURN value respectively.
Edit
MarkL commented:
This is more of an Oracle PL/SQL
question than anything else, I
believe.
I confess that I no nothing about ADO, so I don't know whether the following example will work in your case. It involves building some infrastructure which allows us to pass an array of values into a procedure. The following example creates a new department, promotes an existing employee to manage it and assigns two new hires.
SQL> create or replace type new_emp_t as object
2 (ename varchar2(10)
3 , sal number (7,2)
4 , job varchar2(10));
5 /
Type created.
SQL>
SQL> create or replace type new_emp_nt as table of new_emp_t;
2 /
Type created.
SQL>
SQL> create or replace procedure pop_new_dept
2 (p_dname in dept.dname%type
3 , p_loc in dept.loc%type
4 , p_mgr in emp.empno%type
5 , p_staff in new_emp_nt
6 , p_deptno out dept.deptno%type)
7 is
8 l_deptno dept.deptno%type;
9 begin
10 insert into dept
11 (dname, loc)
12 values
13 (p_dname, p_loc)
14 returning deptno into l_deptno;
15 update emp
16 set deptno = l_deptno
17 , job = 'MANAGER'
18 , mgr = 7839
19 where empno = p_mgr;
20 forall i in p_staff.first()..p_staff.last()
21 insert into emp
22 (ename
23 , sal
24 , job
25 , hiredate
26 , mgr
27 , deptno)
28 values
29 (p_staff(i).ename
30 , p_staff(i).sal
31 , p_staff(i).job
32 , sysdate
33 , p_mgr
34 , l_deptno);
35 p_deptno := l_deptno;
36 end pop_new_dept;
37 /
Procedure created.
SQL>
SQL> set serveroutput on
SQL>
SQL> declare
2 dept_staff new_emp_nt;
3 new_dept dept.deptno%type;
4 begin
5 dept_staff := new_emp_nt(new_emp_t('MARKL', 4200, 'DEVELOPER')
6 , new_emp_t('APC', 2300, 'DEVELOPER'));
7 pop_new_dept('IT', 'BRNO', 7844, dept_staff, new_dept);
8 dbms_output.put_line('New DEPTNO = '||new_dept);
9 end;
10 /
New DEPTNO = 70
PL/SQL procedure successfully completed.
SQL>
The primary keys for both DEPT and EMP are assigned through triggers. The FORALL syntax is a very efficient way of inserting records (it also works for UPDATE and DELETE). This could be written as a FUNCTION to return the new DEPTNO instead, but it is generally considered better practice to use a PROCEDURE when inserting, updating or deleting.
That would be my preferred approach but I admit it's not to everybody's taste.
Edit 2
With regards to performance, bulk operations using FORALL will definitely perform better than a handful of individual inserts. In SQL, set operations are always preferable to record-by-record. However, if we are dealing with only a handful of records each time it can be hard to notice the difference.
Building a PL/SQL collection (what you think of as a temporary table in SQL Server) can be expensive in terms of memory. This is especially true if there are many users running the code, because it comes out of the session level allocation of memory, not the Shared Global Area. When we're dealing with a large number of records it is better to populate an array in chunks, perhaps using the BULK COLLECT syntax with a LIMIT clause.
The Oracle online documentation set is pretty good. The PL/SQL Developer's Guide has a whole chapter on Collections. Find out more.