I am trying to do a trigger delete after I delete a row in databaseA employee table, databaseB author table with the same employeeid will be deleted as well. But after several attempts, it keep prompting trigger with errors without specifying what is the error. Here is my code. Thank you.
DELIMITER //
CREATE OR REPLACE TRIGGER employee_delete
AFTER DELETE on databaseA.employee
FOR EACH ROW
BEGIN
DELETE FROM databaseB.author
WHERE databaseB.author.employeeid = old.employeeid
END;
/
Both the posters above are create. You must finish the actual delete statement with a semicolon ";". Also, "old" and "new" must be prefixed with a colon ":". In addition, the trigger may have some issues with authorization depending on grants, synonyms and authorizations. If I were to guess, the syntax problems are the first issues. If, after that, you still experience problems, you may have a grant issue.
Related
New code I'm trying to code a trigger that doesn't allow duplicate values to ensure a band isn't playing at the same time. I get the below compilation error and can't figure it out:
Pretty new to oracle, so any help would be appreciated.
First of all, you do not need a trigger to prevent duplicate records to be inserted. Create a unique index on band_playing and play_time fields and this will take care of any duplicate records.
Regarding the error message: an insert statement creates a new record, therefore there is no :old version of the record, only a :new one. You would need to execute a select to check if a row with the same values exist in the table. Also, as #Littlefoot noted in his comment, an if must be closed by an end if; statement, which is missing from your code.
I am using sequences to create IDs, so while executing insert stored procedure it will create unique value for ID. But after some time it is losing the definition for the sequence.
Not sure why this is happening again and again and how to solve the problem?
I am using Oracle SQL Developer and in the edit table property there is 'Identity Column' setting. See below:
Next step is setting up trigger and sequence:
It was working fine for some time until this property defaulted. Now it is not there anymore:
Still have this trigger and sequence object in the schema and able to setup again but it will break later.
How to avoid this problem in future?
I think it is just a bug/limitation in your client software, Oracle SQL Developer. The "Identity Column" tab is a handy way to create the corresponding sequence and trigger but it doesn't seem to recognise existing elements. I've just verified my own system and that's exactly what happens.
It makes sense, because adding a new sequence and trigger is a pretty straightforward task (all you need is a template) but displaying current sequence is hard given that a trigger can implement any conceivable logic. Surely it could be done but the cost-benefit ratio probably left things this way.
In short, your app is not broken so nothing needs to be fixed on your side.
This is what I received from IT support regarding the issue:
A few possibilities that might cause this:
1 - Another user with limited privileges might be editing the table using SQL Developer. In this case, if this user's privilege is not enough to obtain the sequence and/or trigger information from the database, the tool might leave the fields blank and disable it when table changes are saved.
2 - The objects are being changed or removed outside of SQL Developer, causing it to lose the information. In my tests I noticed that dropping the trigger and recreating it with the same name caused the identity property information to be lost on SQL Developer.
Even being the trigger enabled, and working for inserts it could not retrieve the information.
Then, if I run an alter trigger to enable it (even tough dba_trigger is reporting it as already enabled), SQL Developer will list the information again:
ALTER TRIGGER "AWS"."TABLE1_TRG" ENABLE;
So it looks like there are some issues with the SQL Developer, that is causing this behavior.
Next time it happen, please check if the trigger still exist on the database and is enabled with the query below:
select owner, trigger_name, TRIGGER_TYPE, TRIGGERING_EVENT, TABLE_OWNER, TABLE_NAME, STATUS
from dba_triggers
where trigger_name = 'ENTER_YOUR_TRG_NAME'; --Just change the trigger name in WHERE
I am new to Oracle and would like to know how to make this trigger work please. I can do each trigger separately but I need them all in the same one if that makes sense.
create trigger ID_trigger
before insert on crime, evidence, offence, officer
for each row
begin
select crime_seq.nextval into :new.crime_id from dual
and officer_seq.nextval into :new.officer_id from dual
and evidence_seq.nextval into :new.evidence_id from dual
and offence_seq.nextval into :new.offence_id from dual;
end;
I initially had a single trigger for each table. However when submitting data into my form the triggers seemed to have overwritten the previous one
" I initially had a singler trigger for each table, however when
sumbitting data into my form the triggers seemed to have overwritten
the previous one"
Let's guess: you called all four triggers id_trigger. Each subsequent CREATE OR REPLACE TRIGGER call would overwrite the first one. Unless you used CREATE TRIGGER as you do here, in which case each subsequent call would fail, Either way, only one table would have a trigger.
You see, even though they belong to a table, triggers are separate database objects. So, like indexes or constraints, their names must be unique within the schema.
The solution is simple: give each trigger a different name, say by including the table name.
I have a table of people who belong to various sites. These sites can change, but don't very often. So when we create an attendance record (a learner_session object) we don't store the site. But this has cause a problem in reporting how many training hours a site has, because some people have changed sites over the years. Not by much, but we'd like to get this right.
So I've added a site_at_the_time column to the learner_session table. I want to auto-populate this with the site the person was at when they attended the session. But I'm not sure how to reference this. For some reason (I'm guessing to speed development or something) the learner_id is allowed to be null. So I'm currently planning to do an update trigger. The learner_id shouldn't ever get updated, and if it ever did somehow, the entire record would be junk so I'm not worried about it overwriting it.
The trigger I have now is
create trigger set_site_at_the_time
after update of learner_id on lrn_session
begin
:new.site_at_the_time:= (select site_id from learner who where :new.learner_id = who.learner_id);
end;
which leads me to the following error:
ORA-04082: NEW or OLD references not allowed in table level triggers
Now, I've done some research and found I need to use a FOR EACH ROW - and I'm wondering what exactly this FOR EACH ROW does - is it every row captured by the trigger? Or is it every row in the table?
Also, will this trigger when I create a record too? So if I do insert into learner_session(id,learner_id,...) values(learner_session_id_seq.nextval,1234,...) will this capture that appropriately?
And while I'm here, I might as well see if there's something else I'm doing wrong with this trigger. But I'm mainly asking to figure out what the FOR EACH ROW is supposed to do and if it triggers properly. =)
FOR EACH ROW means that the trigger will fire once for each row that is updated by your SQL statement. Without this clause, the trigger will only fire once, no matter how many rows are affected. If you want to change values as they're being inserted, you have to use FOR EACH ROW, because otherwise the trigger can't know which :new and :old values to use.
As written, the trigger only fires on update. To make it also fire upon insert, you'd need to change the definition:
CREATE TRIGGER set_site_at_the_time
BEFORE INSERT OR UPDATE OF learner_id
ON lrn_session
FOR EACH ROW
BEGIN
SELECT site_id into :new.site_at_the_time
FROM learner who
WHERE :new.learner_id = who.learner_id);
END set_site_at_the_time;
I apologize for posting a question that seems to have been asked numerous times on the internet, but I can't quite fix it for some reason.
I was trying to populate some tables using Oracle's magical sqldr utility, but it throws an ORA-01775 error for some reason.
Everywhere I go on Google, people say something along the lines of: "Amateur, get your synonyms sorted out" (that was paraphrased) and that's nice and all, but I did not make any synonyms.
Here, the following does not work on my system:
SQLPLUS user/password
SQL>CREATE TABLE test (name varchar(10), id number);
SQL>exit
Then, I have a .ctl file with the following contents:
load data
characterset utf16
infile *
append
into table test
(name,
id
)
begindata
"GURRR" 4567
Then I run this command:
sqlldr user#localhost/password control=/tmp/controlfiles/test.ctl
The result:
SQL*Loader-702: Internal error - ulndotvcol: OCIStmtExecute()
ORA-01775: looping chain of synonyms
Part of test.log:
Table TEST, loaded from every logical record.
Insert option in effect for this table: APPEND
Column Name Position Len Term Encl Datatype
------------------------------ ---------- ----- ---- ---- ---------------------
NAME FIRST 2 CHARACTER
ID NEXT 2 CHARACTER
SQL*Loader-702: Internal error - ulndotvcol: OCIStmtExecute()
ORA-01775: looping chain of synonyms
And, if I try to do a manual insert:
SQL> insert into test values ('aa', 56);
1 row created.
There is no problem.
So, yeah, I am stuck!
If it helps, I am using Oracle 11g XE on CentOS.
Thanks for the help guys, I appreciate it.
EDIT:
I kind of, sort of figured out part of the problem. The problem was that somewhere along the line, maybe during a failed load or something, Oracle had given itself corrupt views and synonyms.
The affected views were: GV_$LOADISTAT, GV_$LOADPSTAT, V_$LOADISTAT and V_$LOADPSTAT. I am not quite sure why the views got corrupt, but recompiling them resulted in compiled with errorserrors. The synonyms used in the queries themselves were corrupt, namely the gv$loadistat, gv$loadpstat, v$loadistat and v$loadpstat synonyms.
I wasn't sure about why this was happening and I didn't quite understand anything. So, I decided to drop the synonyms and recreate them. Unfortunately, I couldn't recreate them, as the view they pointed to (there is a bit of weird recursion going on here...) was corrupt. These views were the aforementioned GV_$LOADISTAT and other views. In other words, the synonyms pointed to the views that used those synonyms. Talk about a looping chain.
So...I recreated the public synonyms but instead of specifying the view as GV_$LOADISTAT, I specified them as sys.GV_$LOADISTAT. e.g.
DROP PUBLIC synonym GV$LOADISTAT;
CREATE PUBLIC synonym GV$LOADISTAT for sys.GV_$LOADISTAT;
Then, I recreated the user views to point to those public synonyms.
CREATE OR REPLACE FORCE VIEW "USER"."GV_$LOADISTAT" ("INST_ID", "OWNER", "TABNAME", "INDEXNAME", "SUBNAME", "MESSAGE_NUM", "MESSAGE")
AS
SELECT "INST_ID",
"OWNER",
"TABNAME",
"INDEXNAME",
"SUBNAME",
"MESSAGE_NUM",
"MESSAGE"
FROM gv$loadistat;
That seemed to fix the views/synonyms. Yeah, it is a bit of a hack, but it somehow worked. Unfortunately, this was not enough to run SQL Loader. I got a table or view does not exist error.
I tried granting more permissions to my regular user, but it didn't work. So, I gave up and ran SQL Loader as sysdba. It worked! It is not a good thing to do, but it is a development only system made for testing purposes, so, I didn't care.
I could not repeat your looping synonym chain error, but it appears the control file needed a bit of work, at least for my environment.
I was able to get your example to work by modifying it thusly:
load data
infile *
append
into table test
fields terminated by "," optionally enclosed by '"'
(name,
id
)
begindata
"GURRR",4567