I'm trying to limit a table to only one record and disable all attempt to add more.
I have created this trigger: CREATE TRIGGER abort_insert_to_my_tbl BEFORE INSERT ON my_tbl
BEGIN
RAISE(ABORT,"You can't add records to my_tbl")
END;
But I keep getting this error:
Error: near line 3080: near "RAISE": syntax error
What am I doing wrong?
As the documentation shows, RAISE is a function, not a statement, so it cannot be used directly in the trigger body.
To use a function in a statement, use, for example, a SELECT statement:
CREATE TRIGGER abort_insert_to_my_tbl
BEFORE INSERT ON my_tbl
BEGIN
SELECT RAISE(ABORT, 'You can''t add records to my_tbl');
END;
Related
I am creating a book tracking database for myself that holds information about my books and allows me to keep track of who is borrowing them. I am trying to create a trigger on my Checkouts table that runs if a record is added or updated that will determine if a checkout data has been entered or if a checkin date has been entered and change the "available" field in my Books table to "Y" or "N".
I have created a trigger called "update_book_availablility" on my Checkouts table but I keep getting this error:
"PLS-00103: Encountered the symbol 'end-of-file' when expecting one of the following: ( begin case declare and exception exit for goto if loop mod null pragma raise return select update while with <<continue close current delete fetch lock insert open rollback savepoint set sql execute commit forall merge standard pipe purge json_object
Errors: check compiler log"
Here is my trigger code:
CREATE OR REPLACE NONEDITIONABLE TRIGGER "UPDATE_BOOK_AVAILABILITY"
AFTER INSERT OR UPDATE OF ISBN, PersonID, checkout_date, checkin_date
ON Checkouts
FOR EACH ROW
BEGIN
IF :NEW.checkout_date = NULL
THEN
UPDATE Book
SET available = 'N'
WHERE ISBN IN (SELECT :NEW.ISBN FROM Checkouts);
END IF;
END;
Here is an image of my ERD:
ERD
I have been looking into and double checking my trigger syntax, If condition syntax, subquery syntax, and googling this error but have found nothing that has helped. I am new to PL/SQL and would appreciate any help in understanding what I have done wrong or missed.
PLS-00103: Encountered the symbol end-of-file error is SYNTAX ERROR
Copied your trigger and adjusted it to one of my test tables - it works. I removed NONEDITIONABLE and changed trigger table name as well as column names and table/column beeing updated by trigger.
To Do:
Check your syntax again or write the trigger from scratch once more
"...WHERE ISBN IN (SELECT :NEW.ISBN FROM Checkouts)..." selects one fixed value (FOR EACH ROW) :NEW.ISBN of triggering table, better ->> "... WHERE ISBN = :NEW.ISBN ..."
Prety sure that you don't need NONEDITIONABLE trigger for your books tracking app...
Regards...
The assignment I am trying to do is
"Create a procedure that places the names of all presidents who were born in one specific
state, in a temporary table. Display the contents of this table."
The procedure complies but when I try to invoke it, it gives me:
00000 - "table or view does not exist"
Error(8,5): PLS-00103: Encountered the symbol "CREATE" when expecting one of the following: begin function pragma procedure subtype type current cursor delete exists prior
I have been stuck for a while now. Does anybody know what I am doing wrong?
My code so far is:
CREATE OR REPLACE PROCEDURE stateofpresident(p_state president.state_born%TYPE)
AS
CURSOR c_state IS
SELECT *
FROM president;
BEGIN
execute immediate 'CREATE TABLE presidentFromState;
(
president_name VARCHAR2
)';
FOR r_state IN c_state LOOP
IF(p_state = r_state.state_born) THEN
execute immediate 'INSERT INTO presidentFromState VALUES(r_state.pres_name)';
commit;
END IF;
END LOOP;
execute immediate 'DROP TABLE presidentFromState';
END stateofpresident;
/
SET SERVEROUT ON
BEGIN
stateofpresident('VIRGINIA');
END;
/
SELECT *
FROM presidentFromState;
The immediate cause of your error is the semi-colon (;) at "presidentFromState;" At run fhat terminates the statement and the SQL interpreter at that point does not know what is want, the create syntax is invalid. The statement compiles because at compile time it is a properly formatted string. That is why dynamic SQL should be avoid if at all possible. Your script also has an additional error. Your last select will fail as the table presidentFromState ws not only created but also dropped in the procedure. Finally, just an FYI, the entire FOR cursor and the cursor itself is entirely unnecessary, the entire operation can be completed is one statement: Look into the structure
Insert into table_name(columns)
Select columns ...
Since this obviously an assignment or tutorial I'll leave the exact for your research.
I'm using sqlte3.8.8, trying to create a trigger to clean old data. Here is the SQL that I put in:
CREATE TRIGGER "main"."NewTrigger" AFTER INSERT ON "historydata"
BEGIN
delete from historydata where id in (select id from historydata order by id limit 100000);
vacuum;
END;
But I got Syntax error on "vacuum;".However, it works fine in sqlite command line.
Is it the case that "vacuum" cannot be used in a trigger?
The documentation shows that only UPDATE/INSERT/DELETE/SELECT statements are allowed in a trigger body.
I wrote the trigger for updating the column value in the same table. For Ex I wrote a trigger on metermaster table after update of assettype column , with in the trigger i am trying to update the instantaneousinterval column in the same metermaster table. Its throws the error like this
ERROR: ORA-04091: table PSEB.METERMASTER is mutating, trigger/function
may not see it.
my trigger code is as follows:
CREATE OR REPLACE TRIGGER PSEB.spiupdate
AFTER
update of assettype
ON pseb.metermaster
referencing new as new old as old
for each row
DECLARE
vassettype number;
resval number(10);
vassettypename varchar2(50);
vmeterid number;
begin
select :new.assettype,:new.meterid INTO vassettype,vmeterid from dual;
select assettypename into vassettypename from pseb.METERASSETINSTTYPE where ASSETTYPEID=vassettype;
select case when assettypename like 'DT' then 86400 when assettypename like 'HT' then 3600 when assettypename like 'FSB' then 86400 end into resval from pseb.meterassetinsttype where assettypename =vassettypename;
update pseb.metermaster set instantaneousinterval=resval where meterid=vmeterid;
end;
I tried to use the
pragma autonomous_transaction;
but it gives the deadlock condition.
ERROR: ORA-00060: deadlock detected while waiting for resource
ORA-06512:
pls help me to fix this issue.
instead of this update statement
update pseb.metermaster set instantaneousinterval=resval where meterid=vmeterid;
use
:new.instantaneousinterval=resval;
A mutating table occurs when a statement causes a trigger to fire and that trigger references the table that caused the trigger. The best way to avoid such problems is to not use triggers, but I suspect the DBA didn’t take the time to do that. He could have done one of the following:
Changed the trigger to an after trigger.
Changed it from a row level trigger to a statement level trigger.
Convert to a Compound Trigger.
Modified the structure of the triggers to use a combination of row and statement level triggers.
Made the trigger autonomous with a commit in it.
Try this pragma autonomous_transaction; with Commit
Since the trigger is updating the same table on which it is defined, why don't you update the two columns in the first update statement itself?
i.e, Instead of using an update like
UPDATE pseb.metermaster
SET assettype = '<v_assettype>';
and relying on trigger to update the instantaneousinterval column, why don't you use an update statement like the following (code is not tested)
UPDATE pseb.metermaster
SET assettype = '<v_assettype>',
instantaneousinterval = (SELECT CASE
WHEN assettypename LIKE 'DT' THEN 86400
WHEN assettypename LIKE 'HT' THEN 3600
WHEN assettypename LIKE 'FSB' THEN 86400
END
FROM pseb.meterassetinsttype
WHERE assettypeid = '<v_assettype>');
In my opinion, using a trigger and autonomous_transaction in this case would be a wrong approach. To know why this is wrong, please search http://asktom.oracle.com/ for this error.
I am a newbie in PLSQL and I would like to create a trigger that checks first if there is a record in a table before making an update.
The code I got so far is:
CREATE OR REPLACE TRIGGER table_bu
BEFORE UPDATE ON employee
FOR EACH ROW
DECLARE
v_employee_id:=employee.employee_ID%TYPE;
BEGIN
SELECT employee_id INTO v_employee_id FROM employee;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE_APPLICATION_ERROR (-20001,'data not found');
END;
How I can create a trigger that checks up if a record exists in the table and if it does not exists does not allow the update.
My table estructure is:
employee_id NUMBER
employee_name VARCHAR(20)
employee_salary NUMBER
...
Thanks
You are on a wrong way. The trigger as it is will throw runtime 'Mutating table' error even after fixing syntax error - you missed semicolon after raise_application_error(also it should take 2 arguments, not one). Correct syntax :
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE_APPLICATION_ERROR (-20001, 'data not found'); -- 1st parameter -error code
Update
As far as I understand the updated version of the question, you want to show error if record doesn't exist. The problem with row level trigger approach is that it won't be executed if nothing is found due to condition in WHERE. The simplest way is to check number of rows affected on client side and raise an error there. Or you can write a procedure that checks sql%rowcount after executing desired update, and then throw an exception if it's 0.
If you prefer to do in a hard way, you can create package variable which of type employee.employee_ID%TYPE, before update statement level trigger that resets variable (say set it to null), after update row level trigger that sets this variable to NEW.employee_ID, and after update statement level trigger that throws an exception if the variable is null. Note: this will properly work for individual updates only.
"How I can create a trigger that checks up if a record exists in the table and if it does not exists does not allow the update."
There is really only one practical way to do this - use a referential constraint (foreign key).