I searched about my issue but couldn't got any solution yet so i am posting it here. I am using Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production.
I have a Main_Table with suppose 10 Records and I have a Log_Table to log (insert) the old and new values on update of new table.
I am using a compound trigger (to avoid mutating errors) to loop through all columns of "Main_Table" dynamically and get the updating row records by filtering through new . Primarykey (UID)).
I hope i am using Compound trigger right.
I am not using :old and :new as I am looping through all columns dynamically and need to match the column values.
But it is again giving me mutating error:
Error report -
SQL Error: ORA-04091: table Main_Table is mutating, trigger/function may not see it
ORA-06512: at "Schema.TRG_TEST", line 87
ORA-04088: error during execution of trigger 'Schema.TRG_TEST'
04091. 00000 - "table %s.%s is mutating, trigger/function may not see it"
*Cause: A trigger (or a user defined plsql function that is referenced in
this statement) attempted to look at (or modify) a table that was
in the middle of being modified by the statement which fired it.
*Action: Rewrite the trigger (or function) so it does not read that table.
Below is my trigger code:
create or replace TRIGGER TRG_TEST
FOR INSERT or UPDATE ON Main_Table
COMPOUND TRIGGER
TYPE NUMBER_TABLE IS TABLE OF NUMBER;
tblTABLE2_IDS NUMBER_TABLE;
TYPE VARCHAR_TABLE IS TABLE OF VARCHAR(2000);
tblTABLE3_IDS VARCHAR_TABLE;
TYPE VARCHAR_TABLE1 IS TABLE OF VARCHAR(2000);
tblTABLE4_IDS VARCHAR_TABLE1;
vcount NUMBER;
colCount NUMBER;
colCountAfter NUMBER;
vvalue VARCHAR2(4000);
vcolumn VARCHAR2(4000);
sql1 VARCHAR2(4000);
dynamicq varchar(4000);
testv varchar(2000);
testv1 varchar(2000);
ssql varchar(2000);
ssql1 varchar(2000);
maxsiteid NUMBER;
newsid varchar(2000);
newstid varchar(2000);
newuid varchar(2000);
--Executed before DML statement
BEFORE STATEMENT IS
BEGIN
tblTABLE2_IDS := NUMBER_TABLE();
tblTABLE3_IDS:= VARCHAR_TABLE();
tblTABLE4_IDS:= VARCHAR_TABLE1();
IF UPDATING THEN
dbms_output.put_line('Before Statement - In Updating');
--dbms_output.put_line('Before Each Row - In Updating');
-- tblTABLE2_IDS.EXTEND;
--tblTABLE2_IDS(tblTABLE2_IDS.LAST) := :new.UID;
END IF;
END BEFORE STATEMENT;
--Executed before each row change- :NEW, :OLD are available
BEFORE EACH ROW IS
BEGIN
IF UPDATING THEN
dbms_output.put_line('Before Each Row - In Updating');
tblTABLE2_IDS.EXTEND;
tblTABLE2_IDS(tblTABLE2_IDS.LAST) := :new.UID;
-- FOR columnlist IN
--(SELECT COLUMN_NAME AS COLUMN_NAME FROM all_tab_columns WHERE lower(TABLE_NAME) = 'Main_Table'
-- AND lower(COLUMN_NAME) NOT IN ( 's_id' ,'msid' ,'st' ,'u_id' ,'db_flag' ))
--LOOP
--colCount:=colCount+1;
--ssql1:='select '||columnlist.COLUMN_NAME||' from Main_Table where UID='||tblTABLE2_IDS(tblTABLE2_IDS.LAST)||'';
--dbms_output.put_line(ssql1);
--execute immediate ssql1 into testv;
--tblTABLE3_IDS(colCount):=testv;
--dbms_output.put_line(testv);
--END LOOP;
END IF;
END BEFORE EACH ROW;
--Executed aftereach row change- :NEW, :OLD are available
AFTER EACH ROW IS
BEGIN
IF UPDATING THEN
dbms_output.put_line('After Each Row - In Updating');
FOR columnlist IN
(SELECT COLUMN_NAME AS COLUMN_NAME FROM all_tab_columns WHERE lower(TABLE_NAME) = 'Main_Table'
AND lower(COLUMN_NAME) NOT IN ( 's_id' ,'msid' ,'st' ,'u_id' ,'db_flag' ))
LOOP
colCount:=colCount+1;
ssql1:='select '||columnlist.COLUMN_NAME||' from Main_Table where UID='||tblTABLE2_IDS(tblTABLE2_IDS.LAST)||'';
dbms_output.put_line(ssql1);
execute immediate ssql1 into testv;
tblTABLE3_IDS(colCount):=testv;
dbms_output.put_line(testv);
END LOOP;
END IF;
END AFTER EACH ROW;
--Executed after DML statement
AFTER STATEMENT IS
BEGIN
IF UPDATING THEN
dbms_output.put_line('After Statement - In Updating');
FOR columnlist IN
(SELECT COLUMN_NAME AS COLUMN_NAME FROM all_tab_columns WHERE lower(TABLE_NAME) = 'Main_Table'
AND lower(COLUMN_NAME) NOT IN ( 's_id' ,'msid' ,'st' ,'u_id' ,'db_flag' ))
LOOP
colCountAfter:=colCountAfter+1;
dbms_output.put_line('loop started');
ssql1:='select '||columnlist.COLUMN_NAME||' from Main_Table where UID='||tblTABLE2_IDS(tblTABLE2_IDS.LAST)||'';
execute immediate ssql1 into testv1;
dbms_output.put_line(testv);
tblTABLE3_IDS(colCountAfter):=testv1;
IF ((testv) IS NOT NULL) THEN
FOR i IN tblTABLE3_IDS.FIRST..tblTABLE2_IDS.LAST LOOP
dbms_output.put_line('Values No :' ||i||' is ' || tblTABLE3_IDS(i) || ' and ' ||tblTABLE4_IDS(i));
IF(tblTABLE3_IDS(i)=tblTABLE4_IDS(i)) THEN
dbms_output.put_line(testv1);
ELSE
-- dbms_output.put_line('select :new.'|| columnlist.COLUMN_NAME||' from dual');
dbms_output.put_line(testv1);
INSERT INTO Log_Table
(
user_id,
log_action,
log_table_name,
schema_name,
log_column_name,
col_old_val,
col_new_val,
ne_type,
ne_id,
system_id
)
VALUES
(
newuid,
'UPDATE',
'Main_Table',
'SCHEMA'
,columnlist.COLUMN_NAME
,tblTABLE3_IDS(i)
,tblTABLE4_IDS(i)
,'S'
,newstid
,newsid
);
END IF;
END LOOP;
END IF;
END LOOP;
END IF;
END AFTER STATEMENT;
END TRG_TEST;
Initially i had tried accessing the updating table in "Before Each Row" then i tried accessing it in "After Each Row", same error in both cases.
I am struggling to find a solution to it even after using compound trigger,however i achieved the same for insert.
Can anyone help in how to achieve it. Thanks in Advance.
Usually an after statement row level trigger is sufficient to fill a logging table.
Old and new column values are available in the :old and :new pseudo records.
A very basic example:
create or replace trigger my_trigger
after insert or update on my_table
for each row
declare
begin
if inserting
then
insert into logging table
(id
,my_column_old
,my_column_new)
values
(:new.id
,null -- no old value in case of insert
,:new.my_column);
else
insert into logging table
(id
,my_column_old
,my_column_new)
values
(:new.id
,:old.my_column
,:new.my_column);
end if;
end;
As I understand from one of your comments you want track history of new added column(users can add and drop column) and you want not recompile trigger.
Then you can use Oracle Total Recall
Happily you have Oracle 12c EE(most bugs are fixed).
Related
i'm creating a trigger that triggers on INSERT on a table,
and i wish to log the structure of tables inserted so i wrote this Function
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column text;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := NEW."COLUMN_NAME";
target_table_name := NEW."TABLE_NAME";
END IF;
SELECT column_name into old_column
FROM information_schema."columns"
WHERE table_schema = 'items'
and table_name = LOWER(NEW."TABLE_NAME")
and column_name = LOWER(NEW."COLUMN_NAME");
if (coalesce(old_column,'')='' or old_column='' or old_column = added_column) THEN
-- If a new column has been added
IF (Lower(added_column) != 'sync') then
-- Add the new column to the target table
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN ' || LOWER(added_column) || ' VARCHAR(50)';
END IF;
end if;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
executed by this TRIGGER :
CREATE TRIGGER update_table_log_received_trigger
AFTER INSERT
ON items."TABLE_LOG_RECEIVED"
FOR EACH ROW
EXECUTE FUNCTION update_table_log_received();
the returned exception is the following :
! ERROR: the column « x » of the relation « y » already exists
Where: instruction SQL « ALTER TABLE items. ADD COLUMN x VARCHAR(50) »
my problem now is that it isn't supposed to pass the If checks (i pasted the code after many alterations i have two if conditions that do the same thing just because),
i debugged and logged the statements to note that the select query inside my function returns null apparently.
i also tried to use "USING NEW" but i am no expert so i couldn't make it work
is it a problem with the declared variable not being populated from the "NEW" record or am i executing the select statement wrong ?
EDIT : tl;dr for my problem, I would like to update a table in Database2 whenever the same table (that had the same structre) is altered from Database1, be it added column or changed column, at this point iI'm stuck at the first problem to add the column.
I am logging my tables' structures as strings into a new table and syncing that with Database2 to then have the trigger alter the same altered table from Database1, hope this makes more sense now.
Database1 log_table that logs all my tables' structures:
Database2 log_table_received that is a copy of log_table that executes
the trigger whenever new values are inserted;
Try this syntax:
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column text;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := new."column_name";
target_table_name := new."table_name";
END IF;
if not exists(select 1 from information_schema."columns" where table_name = target_table_name and column_name = added_column)
then
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN ' || LOWER(added_column) || ' VARCHAR(50)';
end if;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
I tried on my DB this is works. You can change some details yourself.
Fixed; Question should have been :
How to select tables & table columns inside function in postgresql.
References:
How to add column if not exists on PostgreSQL?
How to check if a table exists in a given schema
How to get a list column names and datatypes of a table in PostgreSQL?
Basically information_schema can only be accessed by owner meaning the user or (i) see the result when i query it but it returns FALSE when executed inside a script more details here :
https://stackoverflow.com/a/24089729/15170264
Full trigger after fix with CTE to query the pg_catalog also added ADD COLUMN IF NOT EXISTS in my Execute query just to be safe
CREATE OR REPLACE FUNCTION update_table_log_received()
RETURNS TRIGGER AS $$
DECLARE
added_column TEXT;
target_table_name TEXT;
old_column varchar;
old_table varchar;
BEGIN
-- Check if a new column has been added
IF (TG_OP = 'INSERT') THEN
added_column := NEW."COLUMN_NAME";
target_table_name := NEW."TABLE_NAME";
END IF;
/*
* --------------- --CTE to find Columns of table "Target_table_name" from pg_catalog
*/
WITH cte_tables AS (
SELECT
pg_attribute.attname AS column_name,
pg_catalog.format_type(pg_attribute.atttypid, pg_attribute.atttypmod) AS data_type
FROM
pg_catalog.pg_attribute
INNER JOIN
pg_catalog.pg_class ON pg_class.oid = pg_attribute.attrelid
INNER JOIN
pg_catalog.pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE
pg_attribute.attnum > 0
AND NOT pg_attribute.attisdropped
AND pg_namespace.nspname = 'items'
AND pg_class.relname = 'trace'
ORDER BY
attnum ASC
)
select column_name into old_column from cte_tables where
column_name=LOWER(added_column);
if (old_column is null ) then
-- Add the new column to the target table
old_column := added_column;
EXECUTE 'ALTER TABLE items.' || LOWER(target_table_name)|| ' ADD COLUMN IF NOT EXISTS ' || LOWER(added_column) || ' VARCHAR(50)';
else
old_column := added_column || 'already exists ! ';
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
create TRIGGER update_table_log_received_trigger
AFTER INSERT
ON items."TABLE_LOG_RECEIVED"
FOR EACH ROW
EXECUTE FUNCTION update_table_log_received();
Variable old_column stores the else condition message but i do not return it, would have if it was a simple function.
I want to make a trigger that will insert a value from a connected row. For example I have a table with 3 rows as below:
I create a trigger that will work once row 3 and 4 are deleted (in this case will be deleted at the same time). And I want to record invnr and extinvnr from row 1 based on idparent=id. I cannot seem to make it work though.
CREATE OR REPLACE TRIGGER LOG_DELETEDPAYMENTS
BEFORE DELETE ON payments
FOR EACH ROW
BEGIN
IF :old.invnr IS NULL THEN
INSERT INTO TABLE_LOG_DELETEDPAYMENTS (table_name, invnr, extinvnr, invdate, transactionid, info, createdby, deleted_by, date_of_delete)
values ('payments', :old.invnr, :old.extinvnr, :old.invdate, :old:transactionid, :old.info, :old.createdby, sys_context('userenv','OS_USER'), SYSDATE);
END IF;
END;
How can I incorporate this into the trigger above?
Try it this way:
create or replace TRIGGER LOG_DELETEDPAYMENTS
BEFORE DELETE ON payments
FOR EACH ROW
DECLARE
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
Declare
my_invnr PAYMENTS.INVNR%TYPE;
my_extinvnr PAYMENTS.EXTINVNR%TYPE;
Begin
IF :old.INVNR IS NULL THEN
Select INVNR, EXTINVNR
Into my_invnr, my_extinvnr
From PAYMENTS
Where ID = :old.IDPARENT;
--
INSERT INTO TABLE_LOG_DELETEDPAYMENTS (table_name, invnr, extinvnr, invdate, transactionid, info, createdby, deleted_by, date_of_delete)
values ('payments', my_invnr, my_extinvnr, :old.invdate, :old:transactionid, :old.info, :old.createdby, sys_context('userenv','OS_USER'), SYSDATE);
END IF;
End;
END;
You should select the values of INVNR and EXTINVNR based on ID - IDPARENT relationship and store it in the variables (my_invnr and my_extinvnr).
Those variables are used in INSERT into the log statement.
Because of the Select ... Into statement that is reading the affected table - trigger would fail with table PAYMENTS is mutating error.
To avoid that (to separate transaction from the table) you should Declare the PRAGMA AUTONOMOUS_TRANSACTION.
There will be two rows inserted into LOG as the trigger runs FOR EACH (deleted) ROW.
Regards...
This assumes your are on release 12c or greater of Oracle database.
CREATE OR REPLACE PACKAGE LOG_DELETEDPAYMENTS_PKG
AS
-- need a locally defined type for use in trigger
TYPE t_payments_tbl IS TABLE OF payments%ROWTYPE INDEX BY PLS_INTEGER;
END LOG_DELETEDPAYMENTS_PKG;
CREATE OR REPLACE PACKAGE BODY LOG_DELETEDPAYMENTS_PKG
AS
BEGIN
-- could also put the trigger code here and pass the type as a parameter to a procedure
NULL;
END LOG_DELETEDPAYMENTS_PKG;
CREATE OR REPLACE TRIGGER LOG_DELETEDPAYMENTS_CT
FOR DELETE ON payments
COMPOUND TRIGGER
l_tab LOG_DELETEDPAYMENTS_PKG.t_payments_tbl;
l_count PLS_INTEGER:= 0;
BEFORE EACH ROW IS
BEGIN
-- capture the deletes in local type
l_count := l_count + 1;
l_tab(l_count).invnr := :old.invnr;
l_tab(l_count).extinvnr := :old.extinvnr;
l_tab(l_count).invdate := :old.invdate;
l_tab(l_count).transactionid := :old.transactionid;
l_tab(l_count).info := :old.info;
l_tab(l_count).createdby := :old.createdby;
l_tab(l_count).idparent := :old.idparent;
l_tab(l_count).id := :old.id;
END BEFORE EACH ROW;
AFTER STATEMENT IS
BEGIN
FOR i IN l_tab.first .. l_tab.COUNT LOOP
IF(l_tab(i).invnr IS NULL) THEN
-- if the invoice number is NULL, then get info from parent
SELECT p.invnr
,p.extinvnr
INTO l_tab(i).invnr
,l_tab(i).extinvnr
FROM TABLE(l_tab) p
WHERE p.id = l_tab(i).idparent;
END IF;
END LOOP;
-- log all deletes
FORALL i IN 1 .. l_tab.COUNT
INSERT INTO LOG_DELETEDPAYMENTS
(table_name, invnr, extinvnr, invdate, transactionid, info, createdby, deleted_by, date_of_delete)
VALUES
('payments', l_tab(i).invnr, l_tab(i).extinvnr, l_tab(i).invdate, l_tab(i).transactionid, l_tab(i).info, l_tab(i).createdby, sys_context('userenv','OS_USER'), SYSDATE);
l_tab.delete;
END AFTER STATEMENT;
END LOG_DELETEDPAYMENTS_CT;
I'm trying to create a procedure that given a table name, it will create a sequence and auto incrementing trigger, all using variables based on the table name.
Code :
CREATE OR REPLACE procedure CREATE_SEQUENTIAL_TR(table_name VARCHAR)
is -- Tried using declare but it wouldn't accept
coluna_cod varchar(100 char);
begin
--Finding the cod column name for this table first
--They start with "PK_CD"
select
COLUMN_NAME
into
coluna_cod
from
ALL_TAB_COLUMNS
where
TABLE_NAME=table_name
and COLUMN_NAME like "PK_CD%";
--Creating the sequence obj
drop sequence "cod" || table_name;
create sequence "cod" || table_name;
--Now creating the trigger
create or replace trigger "cod" || table_name || "tr"
before
UPDATE or INSERT on table_name
for each row
declare
cod number := coluna_cod;
tr_name varchar(100 char) := "cod" || table_name
begin
if UPDATING then
if :new.cod != :old.cod then
:new.cod := :old.cod;
end if;
else -- inserting
:new.cod := tr_name.nextval();
end if;
end;
end;
The complexity of this ended up quite out of the scope of my knowledge.
At the moment it is giving an error on drop sequence "cod" || table_name (Unexpected DROP symbol found) but I'm sure I have made other errors.
Can someone help me figure this logic out?
You can't put DDL statements (like drop or create or alter) directly inside a PL/SQL block. If you want to do DDL inside PL/SQL, you can do an execute immediate:
declare
begin
drop sequence X; -- error
execute immediate 'drop sequence X'; -- works fine
end;
/
Can some one please guide me what's wrong with this query? In SQL Server we just check the presence of the Object_ID of a table to drop it and re-create it. I am new to Oracle and wrote this query:
declare Table_exists INTEGER;
BEGIN
Select count(*) into Table_exists from sys.all_tables where table_name='TABLENAME1';
EXCEPTION
WHEN NO_DATA_FOUND
THEN
Table_Exists :=0;
if(table_exists)=1
Then
Execute Immediate 'Drop Table TABLENAME1;'
'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('Table Dropped and Re-Created!');
Else
Execute Immediate 'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('New Table Created!');
END IF;
END;
I get the output - ANONYMOUS BLOCK COMPLETED, but the table is not created. The table was previously existing, so I dropped it to check if the PL/SQL is actually creating the table, but NO. What is wrong here? What am I missing? Please guide.
When you are using all_tables filter the results for your
schema by adding where owner = 'your_schema'
or use sys.user_tables
ALL_TABLES describes the relational tables accessible to the current user
USER_TABLES describes the relational tables owned by the current user.
When use execute_emmidiate remove the ; from the query;
Modified query;
DECLARE
Table_exists INTEGER;
BEGIN
Select count(*) into Table_exists from sys.user_tables where table_name='TABLENAME1';
--or
--Select count(*) into Table_exists from sys.all_tables
--where table_name='TABLENAME1' and owner = 'your_DB';
if table_exists = 1 Then
Execute Immediate 'Drop Table TABLENAME1';
Execute Immediate 'Create Table TABLENAME1(num number)';
DBMS_OUTPUT.PUT_LINE('Table Dropped and Re-Created!');
Else
Execute Immediate 'Create Table TABLENAME1(num number)';
DBMS_OUTPUT.PUT_LINE('New Table Created!');
END IF;
END;
First note:
Select count(*) into Table_exists
from sys.all_tables
where table_name = 'TABLENAME1';
will always return one row. You don't need the exception handling.
My best guess is that you have more than one table called TABLENAME1. Run this query to find out:
Select *
from sys.all_tables
where table_name = 'TABLENAME1';
Oracle stores tables from all owners that you can access. You might also want to check OWNER_NAME in the where clause.
However, you seem to understand exception handling. So, just drop the table, ignore any errors, and then recreate the table.
The EXCEPTION clause lasts till the next END and not just the next statement. If you want to continue after catching the exception you need to add an additional BEGIN/END:
declare
Table_exists INTEGER;
BEGIN
BEGIN
Select count(*) into Table_exists from sys.all_tables where table_name='TABLENAME1';
EXCEPTION
WHEN NO_DATA_FOUND THEN
Table_Exists :=0;
END;
if(table_exists)=1 Then
Execute Immediate 'Drop Table TABLENAME1;'
Execute Immediate 'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('Table Dropped and Re-Created!');
Else
Execute Immediate 'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('New Table Created!');
END IF;
END;
As pointed out by Gordon, the EXCEPTION clause is not really needed in this case since count(*) will always return one row. So the following is sufficient:
declare
Table_exists INTEGER;
BEGIN
Select count(*) into Table_exists from sys.all_tables where table_name='TABLENAME1';
if(table_exists)=1 Then
Execute Immediate 'Drop Table TABLENAME1;'
Execute Immediate 'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('Table Dropped and Re-Created!');
Else
Execute Immediate 'Create Table TABLENAME1;';
DBMS_OUTPUT.PUT_LINE('New Table Created!');
END IF;
END;
CREATE OR REPLACE TRIGGER P88
AFTER INSERT ON reparation
FOR EACH ROW
DECLARE
vope number;
BEGIN
SELECT observation_reparation into vope from repartion;
if(vope IS NULL)THEN
EXECUTE IMMEDIATE 'ALTER TABLE ' || reparation.observations_Reparation || ' MODIFY libelle_piece NVARCHAR2(50)';
END IF;
END;
/
I get this:
error:table or view does not exist.
CREATE OR REPLACE TRIGGER P88
AFTER INSERT ON reparation
FOR EACH ROW
DECLARE
vope number;
BEGIN
SELECT observation_reparation into vope from repartion;
if(vope IS NULL)THEN
EXECUTE IMMEDIATE 'ALTER TABLE reparation RENAME COLUMN observations_Reparation TO libelle_piece';
END IF;
END;
if you also need to change the declaration of the column you will need another ALTER statement
alter table reparation modify (libelle_piece NVARCHAR2(50))