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Oracle SQL Insert Trigger to Hash Password is not working (Issue with CHAR)
(3 answers)
Closed 1 year ago.
I am working on a requirement.
I have to apply trigger to mask data to a particular column in the database.
The table has 4 columns, firstName, lastName, userID, password. I want to write a trigger that masks the passsword column.
Here is the trigger, but its not working as expected.
CREATE OR REPLACE TRIGGER dmm_live.TRG_I_TUSER_PASSWORD_HASHING
AFTER INSERT OR UPDATE ON dmm_live.SampleHashPassword
FOR EACH ROW
DECLARE
/* Package :
* Author :
* Created :
* Description : Trigger
*
*/
vType VARCHAR2(1);
BEGIN
IF INSERTING THEN
vTYPE := 'I';
ELSIF UPDATING THEN
vType := 'U';
END IF;
IF INSERTING OR UPDATING THEN
INSERT INTO dmm_live.SampleHashPassword (password) values utl_i18n.STRING_TO_RAW(password, 'AL32UTF8');
--SET PASSWORD =utl_i18n.STRING_TO_RAW(PASSWORD, 'AL32UTF8');
END IF;
EXCEPTION WHEN OTHERS THEN
NULL;
Can anyone please help?
In a trigger you can set or change the values of a column in the updated table - that is done by referencing the column as a bind variable. Basically this is invoked during the dml process, so you wouldn't do a insert into the table (remember you're in the actual insert process).
I removed the unused lines of code.
One remark... WHEN OTHERS THEN NULL; is very scary. That means you don't care if anything goes wrong. I would want to see the error, log it and probably display an error in the application as well...
CREATE OR REPLACE TRIGGER dmm_live.TRG_I_TUSER_PASSWORD_HASHING
AFTER INSERT OR UPDATE ON SampleHashPassword
FOR EACH ROW
DECLARE
/* Package :
* Author :
* Created :
* Description : Trigger
*
*/
vType VARCHAR2(1);
BEGIN
:NEW.SampleHashPassword := utl_i18n.STRING_TO_RAW(password, 'AL32UTF8');
--SET PASSWORD =utl_i18n.STRING_TO_RAW(PASSWORD, 'AL32UTF8');
EXCEPTION WHEN OTHERS THEN
NULL;
END dmm_live.TRG_I_TUSER_PASSWORD_HASHING;
Related
The entire question I'm trying to answer is:
Utilize the travel anywhere database to create a database trigger "hotel_kids_rule" to enforce a business rule. when inserting a hotel_reservation, if the num_kids value is more than zero, then assign the bed_type DQ to the reservation. save the trigger source as a script file.
For example, the trigger will change the bed_type for the following insert statement.
insert into hotel_reservation (reserve_no,reserve_date,arrival_date,dep_date,num_adults,num_kids,customer_id,hotel_id,bed_type,rooms)
values(hotel_reserve_sequence.nextval,sysdate,sysdate+5,sysdate+7,1,2,101,19,'DT',1);
For example, the trigger will not change the bed_type for the following insert statement.
insert into hotel_reservation (reserve_no,reserve_date,arrival_date,dep_date,num_adults,num_kids,customer_id,hotel_id,bed_type,rooms)
values(hotel_reserve_sequence.nextval,sysdate,sysdate+5,sysdate+7,2,0,102,20,'DT',1);
This is what I have so far:
create or replace trigger hotel_kids_rule
after insert or update on hotel_reservation
for each row
when (num_kids > 0)
declare
new_bed_type varchar2(20);
new_bed_type='DQ'
begin
new.bed_type=new_bed_type;
end;
Any help would be appreciated! Thanks!
I think you want a before trigger, so you can set the new value before it is written. Also, the way you access new is not ok: within the trigger code, you need :new.bed_type; in the when condition, you want new.num_kids.
This should work:
create or replace trigger hotel_kids_rule
before insert or update on hotel_reservation
for each row
when (new.num_kids > 0)
begin
:new.bed_type := 'DQ';
end;
/
Here is a small demo.
The assignment of your variable needs to be inside the actual code block. And the assignment operator is := in PL/SQL, not =. If you want the trigger to change anything you also need to create it as a BEFORE trigger:
create or replace trigger hotel_kids_rule
before insert or update on hotel_reservation
for each row
when (new.num_kids > 0)
declare
new_bed_type varchar2(20);
begin
new_bed_type := 'DQ';
:new.bed_type := new_bed_type;
end;
Note that the new record in the when condition is used without the colon : while inside the code block it needs to be referenced with the colon.
Alternatively initialize the variable when declaring it:
declare
new_bed_type varchar2(20) := 'DQ';
begin
:new.bed_type := new_bed_type;
end;
Or even simpler without any intermediate variable.
begin
:new.bed_type := 'DQ';
end;
I am new to learning Oracle. I have a task in which I need to update value of any previous record if new record contains its reference.
Table structure is as below :
Review_Table
(review_id number pk,
review_name varchar2,
previous_review number null,
followup_review number null
)
Here previous_review and followup_review columns are objects of same table i.e Review_table.
Now consider we have two records in Review_table A and B, A does not have any previous or followup review. When user creates/updates the record B and he selects record A as previous record, then we want to automatically update (via trigger) the value of A record's followup review with B's Review ID.
I have tried writing following trigger
create or replace trigger "REVIEW_T1"
AFTER insert or update on "REVIEW_TABLE"
for each row
begin
update REVIEW_TABLE
set review_follow_up_review = :new.REVIEW_ID
where REVIEW_ID = :new.REVIEW_PREVIOUS_REVIEW;
end;
But I am getting error as : REVIEW_TABLE is mutating, trigger/function may not see it ORA-06512
I have tried searching everything but was unable to find any solution for it
TL;DR: No trigger, no mutating. Do not use trigger to change another row in the same table.
I absolutely agree with #StevenFeuerstein's comment:
I also suggest not using a trigger at all. Instead, create a package that contains two procedures, one to insert into table, one to update. And within these procedures, implement the above logic. Then make sure that the only way developers and apps can modify the table is through this package (don't grant privs on the table, only execute on the package).
Take a look at the following example.
Prepare the schema:
create table reviews (
id number primary key,
name varchar2 (32),
previous number,
followup number
);
create or replace procedure createNextReview (name varchar2, lastId number := null) is
lastReview reviews%rowtype;
nextReview reviews%rowtype;
function getLastReview (lastId number) return reviews%rowtype is
begin
for ret in (
select * from reviews where id = lastId
for update
) loop return ret; end loop;
raise_application_error (-20000, 'last review does not exist');
end;
procedure insertReview (nextReview reviews%rowtype) is
begin
insert into reviews values nextReview;
exception when others then
raise_application_error (-20000, 'cannot insert next review');
end;
procedure setFollowUp (nextId number, lastId number) is
begin
update reviews set
followup = nextId
where id = lastId
;
exception when others then
raise_application_error (-20000, 'cannot update last review');
end;
begin
if lastId is not null then
lastReview := getLastReview (lastId);
end if;
nextReview.id := coalesce (lastReview.id, 0)+1;
nextReview.name := name;
nextReview.previous := lastId;
insertReview (nextReview);
if lastReview.Id is not null then
setFollowUp (nextReview.id, lastReview.Id);
end if;
exception when others then
dbms_output.put_line (
'createNextReview: '||sqlerrm||chr(10)||dbms_utility.format_error_backtrace ()
);
end;
/
Execute:
exec createNextReview ('first review')
exec createNextReview ('next review', 1)
See the outcome of work done:
select * from reviews;
ID NAME PREVIOUS FOLLOWUP
---------- ---------------- ---------- ----------
1 first review 2
2 next review 1
First you need to read about triggers, mutating table error and compound triggers: http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/triggers.htm#LNPLS2005
Your trigger is AFTER UPDATE OR INSERT. Means if you run UPDATE OR INSERT statements on this table, the trigger will fire. But you are trying to update the same table again inside your trigger, which is compl. wrong.
I think you can fix this by rewriting this as a before trigger, rather than an after trigger.
My task is pretty much simple let's say I have table having 3 columns i.e. temp(ids, name_c, UID_c) and I have first two column values and 3rd column is nullable. What I want to do is whenever these two value is inserted the value of third column must be updated (after insertion) with new value. i.e concatenation of both values.
For Ex.
insert into temp(ids, name_c) values(did.nextval,'Andrew');
The result should be
1 Andrew Andrew_1
So I am using trigger for this purpose
create or replace trigger triggerDemo
after INSERT
on temp
for each row
declare
/* pragma autonomous_transaction;*/
user_name varchar2(50);
current_val number;
begin
select did.currval into current_val from dual; /* did is sequence */
select names into user_name from temp where ids = current_val;
update temp set uid_c = user_name||'_'||ids where ids = current_val;
end;
When I am inserting the values I get this error
01403. 00000 - "no data found"
*Cause: No data was found from the objects.
*Action: There was no data from the objects which may be due to end of fetch.
First, you want a before insert trigger, not an after insert trigger. Second, decide whether you want to calculate the id on input or in the trigger. You can do something like this:
create or replace trigger triggerDemo before INSERT on temp
for each row
/* pragma autonomous_transaction;*/
begin
if :new.current_val is null then
select did.currval into :new.ids from dual; /* did is sequence */
end;
select :new.user_name || '_' || :new.ids into :new.uid_c from dual;
end;
I have a requirement of which I want to create a trigger in Oracle.
So what I want is: I have a table called XXCUS.XXACL_PN_PROSPECT_TRL in which there is a column called ACTION whose default value is set as RELEASE, EXTEND and CANCEL.
So my trigger would be on the table XXCUS.XXACL_PN_PROSPECT_TRL as
whenever the column ACTION has values as
RELEASE then the other table column should get UPDATED as R with the same matching ID
EXTEND then the other table column should get UPDATED as O with the same matching ID
CANCEL then the other table column should get UPDATED as C with the same matching ID
The other table name is xxcus.xxacl_pn_leases_all whose column needs to be updated. Also the column name is CLOSE_FLAG.
I m trying like below
CREATE [ OR REPLACE ] TRIGGER XXACL_PN_PROSPECT_T
BEFORE INSERT
ON XXCUS.XXACL_PN_PROSPECT_TRL
[FOR EACH ROW]
DECLARE
-- variable declaration
BEGIN
-- trigger code
Insert into XXCUS.XXACL_PN_PROSPECT_TRL -- values for ACTION here
then
update xxcus.xxacl_pn_leases_all if 'RELEASE' then 'R', if 'EXTEND' then 'O' where mkey = dynamic
EXCEPTION
WHEN ...
-- exception handling
END;
but it is not working as I am not champ in creating Triggers. Kindly help me with this
There are some obvious syntax errors
You don't need square brackets. Those are in the documentation to indicate optional parts.
Your insert/update statements are wrong, need to correct them.
It should look on the lines of :
CREATE OR REPLACE TRIGGER XXACL_PN_PROSPECT_T
BEFORE INSERT
ON XXCUS.XXACL_PN_PROSPECT_TRL
DECLARE
-- variable declaration
BEGIN
UPDATE xxcus.xxacl_pn_leases_all
SET CLOSE_FLAG = DECODE(:NEW.ACTION, 'RELEASE','R','EXTEND','O', 'CANCEL','C')
WHERE ID = :NEW.ID
END;
This trigger will update CLOSE_FLAG column of xxcus.xxacl_pn_leases_all based on what value comes in Action column of XXACL_PN_PROSPECT_TRL table.
While going through the links and documentation, I tried my self and figured out the solution.
There were many syntax errors in the starting. But I guess, I was the only one to apply the exact logic and took help of the syntax online.
So here it was my TRIGGER which I wrote and it worked perfectly.
CREATE OR REPLACE TRIGGER xxcus.xxacl_pn_prospect_trl_trg
AFTER INSERT OR UPDATE
ON xxcus.xxacl_pn_prospect_trl
FOR EACH ROW
DECLARE
sql_error VARCHAR (10000);
v_mkey NUMBER;
v_action VARCHAR (10);
BEGIN
v_action := :NEW.action;
IF (v_action = 'Extend')
THEN
UPDATE xxcus.xxacl_pn_leases_all
SET no_of_days = :NEW.current_action_days
WHERE lease_num = :NEW.lease_no;
ELSIF (v_action = 'Release')
THEN
UPDATE xxcus.xxacl_pn_leases_all
SET no_of_days = 0,
close_flag = 'R'
WHERE lease_num = :NEW.lease_no;
ELSE
UPDATE xxcus.xxacl_pn_leases_all
SET no_of_days = 0,
close_flag = 'C'
WHERE lease_num = :NEW.lease_no;
END IF;
EXCEPTION
WHEN OTHERS
THEN
sql_error := SQLERRM; END;/
I am trying to create a trigger, so that when ever I add a new record it adds another record in the same table. The session field will only take values between 1 and 4. So when I add a 1 in session I want it to add another record but with session 3 blocked. But the problem is that it leads to cascading triggers and it inserts itself again and again because the trigger is triggered when inserted.
I have for example a simple table:
CREATE TABLE example
(
id SERIAL PRIMARY KEY
,name VARCHAR(100) NOT NULL
,session INTEGER
,status VARCHAR(100)
);
My trigger function is:
CREATE OR REPLACE FUNCTION add_block() RETURNS TRIGGER AS $$
BEGIN
INSERT INTO example VALUES (NEW.id + 1, NEW.name, NEW.session+2, 'blocked');
RETURN NULL;
END;
$$ LANGUAGE 'plpgsql';
Trigger is:
CREATE TRIGGER add_block
AFTER INSERT OR UPDATE
ON example
FOR EACH ROW
EXECUTE PROCEDURE add_block();
I get error:
SQL statement "INSERT INTO example VALUES ( $1 +1, $2 , $3 + 2, $4)"
PL/pgSQL function "add_block" line 37 at SQL statement
This error repeats itself so many times that I can't see the top.
How would I solve this?
EDIT:
CREATE TABLE block_rules
(
id SERIAL PRIMARY KEY
,session INTEGER
,block_session INTEGER
);
This table holds the block rules. So if a new record is inserted into the EXAMPLE table with session 1 then it blocks session 3 accordingly by inserting a new record with blocked status in the same (EXAMPLE) table above (not block_rules). Same for session 2 but it blocks session 4.
The block_rules table holds the rules (or pattern) to block a session by. It holds
id | session | block_session
------------------------------
1 | 1 | 3
2 | 2 | 4
3 | 3 | 2
How would I put that in the WHEN statement of the trigger going with Erwin Branstetter's answer below?
Thanks
New answer to edited question
This trigger function adds blocked sessions according to the information in table block_rules.
I assume that the tables are linked by id - information is missing in the question.
I now assume that the block rules are general rules for all sessions alike and link by session. The trigger is only called for non-blocked sessions and inserts a matching blocked session.
Trigger function:
CREATE OR REPLACE FUNCTION add_block()
RETURNS TRIGGER AS
$BODY$
BEGIN
INSERT INTO example (name, session, status)
VALUES (NEW.name
,(SELECT block_session
FROM block_rules
WHERE session = NEW.session)
,'blocked');
RETURN NULL;
END;
$BODY$ LANGUAGE plpgsql;
Trigger:
CREATE TRIGGER add_block
AFTER INSERT -- OR UPDATE
ON example
FOR EACH ROW
WHEN (NEW.status IS DISTINCT FROM 'blocked')
EXECUTE PROCEDURE add_block();
Answer to original question
There is still room for improvement. Consider this setup:
CREATE OR REPLACE FUNCTION add_block()
RETURNS TRIGGER AS
$BODY$
BEGIN
INSERT INTO example (name, session, status)
VALUES (NEW.name, NEW.session + 2, 'blocked');
RETURN NULL;
END;
$BODY$ LANGUAGE plpgsql;
CREATE TRIGGER add_block
AFTER INSERT -- OR UPDATE
ON example
FOR EACH ROW
WHEN (NEW.session < 3)
-- WHEN (status IS DISTINCT FROM 'blocked') -- alternative guess at filter
EXECUTE PROCEDURE add_block();
Major points:
For PostgreSQL 9.0 or later you can use a WHEN condition in the trigger definition. This would be most efficient. For older versions you use the same condition inside the trigger function.
There is no need to add a column, if you can define criteria to discern auto-inserted rows. You did not tell, so I assume that only auto-inserted rows have session > 2 in my example. I added an alternative WHEN condition for status = 'blocked' as comment.
You should always provide a column list for INSERTs. If you don't, later changes to the table may have unexpected side effects!
Do not insert NEW.id + 1 in the trigger manually. This won't increment the sequence and the next INSERT will fail with a duplicate key violation.
id is a serial column, so don't do anything. The default nextval() from the sequence is inserted automatically.
Your description only mentions INSERT, yet you have a trigger AFTER INSERT OR UPDATE. I cut out the UPDATE part.
The keyword plpgsql doesn't have to be quoted.
OK so can't you just add another column, something like this:
ALTER TABLE example ADD COLUMN trig INTEGER DEFAULT 0;
CREATE OR REPLACE FUNCTION add_block() RETURNS TRIGGER AS $$
BEGIN
IF NEW.trig = 0 THEN
INSERT INTO example VALUES (NEXTVAL('example_id_seq'::regclass), NEW.name, NEW.session+2, 'blocked', 1);
END IF;
RETURN NULL;
END;
$$ LANGUAGE 'plpgsql';
it's not great, but it works :-)
CREATE OR REPLACE FUNCTION add_block() RETURNS TRIGGER AS $$
BEGIN
SET SESSION session_replication_role = replica;
INSERT INTO example VALUES (NEXTVAL('example_id_seq'::regclass), NEW.name, NEW.session+2, 'blocked');
SET SESSION session_replication_role = origin;
RETURN NULL;
END;
$$ LANGUAGE 'plpgsql';