Using commit in Trigger in Oracle 11g - oracle

I have created the following trigger in oracle-
create or replace TRIGGER TODAY_TD_INSERT AFTER INSERT ON table1
FOR EACH ROW
DECLARE
BEGIN
INSERT INTO table2 (col1
,col2
,col3
)
VALUES (:NEW.,col1
,:NEW.,col2
,:NEW.,col3
);
END;
So if any data insert in table1 the same data is inserting in table 2 also. So my question is do i need commit the data in new table2 ? So far i know we cannot use commit from trigger.

No, you do not. The session that made the change to the table on which the trigger is placed issues the commit (or rollback), and that applies to all changes made by that session.

Related

Oracle. Select data from one session but commit it to another. Is it possible?

Probably I ask for the impossible, but I'll ask anyway.
Is there an easy way to select from one Oracle session and then insert/commit into another?
(I guess, technically it could be done with pl/sql procedure calls and PRAGMA AUTONOMUS Transactions, but it would be a hassle)
I have the following scenario:
I run some heavy calculations and update / insert into some tables.
After the process is completed I would like to 'backup' the results
(create table as select or insert into another temp table) and then rollback my current session without loosing the backups.
Here is desired/expected behavior:
Oracle 11g
insert into TableA (A,B,C) values (1,2,3);
select * from TableA
Result: 1,2,3
create table [in another session] TempA
as select * from TableA [in this session];
rollback;
select * from TableA;
Result null
select * from TempA;
Result 1,2,3
Is this possible?
Is there an easy way to select from one Oracle session and then insert/commit into another?
Create a program in a third-party language (C++, Java, PHP, etc.) that opens two connections to the database; they will have different sessions regardless of whether you connect as different users or both the same user. Read from one connection and write to the other connection.
you can insert your "heavy calculation" into a Oracle temp Table .
CREATE GLOBAL TEMPORARY TABLE HeavyCalc (
id NUMBER,
description VARCHAR2(20)
)
ON COMMIT DELETE ROWS;
the trick is that when you commit the transaction all rows are deleted from temporary table.
Then you first insert data into the temp table, copy the result to you backup table and commit the transaction.

How to get the table name in trigger on which ddl operation will be performed

I want to do something like
create or replace trigger t1 before ddl on database
begin
insert into table1 values(//the table name on which the ddl will be performed);
end;
so if i create a table named "Hello" than "Hello"(table name) will be inserted in table1
so i don't know how to fetch the table name actually
That's show here in the Database Docs
So you could do something like...
CREATE OR REPLACE TRIGGER ddl_trig
AFTER DDL
ON DATABASE
BEGIN
INSERT INTO loguser.ddl_log
(user_name, ddl_date, ddl_type,
object_type, owner,
object_name)
VALUES
(ora_login_user, SYSDATE, ora_sysevent,
ora_dict_obj_type, ora_dict_obj_owner,
ora_dict_obj_name);
END ddl_trig;
/
BUT, you shouldn't build your own auditing software/code. You should instead use the database's built in auditing system.
See this.
Disclaimer: I work for Oracle and am a product manager on the database team.

Apex Oracle How To Create Conditional Column

I am new to using Apex Oracle to create a table and insert values in it. I need to create a column that is only mandatory if the value for another column is "Y" (if it is "N", then it is not mandatory). The type of the other column is a CHAR with length 1. How could I do this? Would this be done in SQL Scripts or SQL Commands? Similarly, is there a way to delete old SQL commands that were used (that now I realize are incorrect)?
Thank you!
Welcome to Oracle APEX and Stack Overflow. You can create objects (tables/views) in both SQL commands and SQL Scripts. For ad hoc creating, SQL Commands is probably easier. To remove (called "drop" in oracle) objects that you create, that can be done in SQL Commands, or even easier in the "Object Browser" - locate the object and select "drop". Note that this cannot be undone.
About the requirement for a column to be conditionally mandatory:
This can be enforced in the database using a check constraint.
CREATE TABLE test_table (
id NUMBER GENERATED AS IDENTITY,
col1 VARCHAR2(1),
col2 VARCHAR2(10));
Table TEST_TABLE created.
ALTER TABLE test_table ADD CONSTRAINT test_table_c1
CHECK ((col1 = 'Y' AND col2 IS NOT NULL) or (col1 != 'Y'));
Table TEST_TABLE altered.
INSERT INTO test_table(col1,col2) VALUES ('N',NULL);
1 row inserted.
INSERT INTO test_table(col1,col2) VALUES ('Y',NULL);
INSERT INTO test_table(col1,col2) VALUES ('Y',NULL)
Error report -
ORA-02290: check constraint (SAMPLEAPPS.TEST_TABLE_C1) violated
INSERT INTO test_table(col1,col2) VALUES ('Y','Some Value');
1 row inserted.

Rollback and drop table while exception handling in pl sql

Here is the scenario, I am writing a procedure which performs DML(insert) operations on multiple tables. In case of exception I need to rollback data from most of two table and drop a newly created table.
Example:
Procedure{
1 create table1
2 insert into table2
3 insert into table3
Exception
WHEN OTHERS THEN
IF DBMS_SQL.IS_OPEN(cur) THEN
DBMS_SQL.CLOSE_CURSOR(cur);
END IF;
RAISE;
}
Now the question is that if insert fails on table2 then I need to drop table1 as well and if insert fails on table3 then I need to rollback the insert that has already happened on table2 and also drop table1.
I'm not sure how to do that in the "Exception" part of pl-sql procedure. Any help would be highly appreciated. Though I looked at this Create oracle table with auto commit on but this scenario doesn't match mine 100% (somewhat though). All suggestion will be highly apprecaited.
according to the question and comments, using SAVEPOINT is a good idea for this scenario:
1 create table1;
SAVEPOINT SPT;
2 insert into table2;
3 insert into table3;
Exception
WHEN OTHERS THEN
--your code;
ROLLBACK TO SPT;
DROP TABLE table1;

Creating a back up table trigger in Oracle

I have a table A which is constantly updated ( insert statements ) by one application. I want to create another table B which consists only few columns of table A. For this I thought of creating a trigger which triggered after insert on Table A, but I don't know how should I write the insert statement inside the trigger. I am not a database expert, so may be I am missing something simple. Please help.
Here is my trigger code:
CREATE OR REPLACE TRIGGER "MSG_INSERT_TRIGGER"
AFTER
insert on "ACTIVEMQ_MSGS"
DECLARE
PRAGMA AUTONOMOUS_TRANSACTION;
begin
execute immediate 'truncate table MSG_BACKUP';
insert into MSG_BACKUP select * from ACTIVEMQ_MSGS;
COMMIT;
end;
This does not seem to be good idea: every time a new record gets inserted into Table A, delete everything from table B and copy all records from table A. This will be a huge performance issue, once there is many records in table A.
Wouldn't it be enough to create a view on the desired columns of table A?
If not, that is, you still want to "log" all inserts into an other table, then here you go. (I suppose you want to copy the following fields: f1, f2, f3)
CREATE OR REPLACE TRIGGER TR_AI_ACTIVEMQ_MSGS
AFTER INSERT ON ACTIVEMQ_MSGS
FOR EACH ROW
BEGIN
INSERT INTO MSG_BACKUP (f1, f2, f3)
VALUES (:new.f1, :new.f2, :new.f3);
END TR_AI_ACTIVEMQ_MSGS;
Inside an Oracle trigger the record values are available in de :new pseudo record. Your insert statement may look like this:
insert into B (column1, column2)
values (:new.tableA_col1,:new.tableA_col2)

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