I was hoping one of you Oracle experts would be able to give me a hand with this. I have the following SQL Server script, but I need to rewrite it for Oracle:
USE mydb
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE trigger mydb . [CONNECTERTRIGGER] on mydb . [DtreeNotify]
FOR INSERT AS
BEGIN
IF ##ROWCOUNT=0
RETURN
SET IDENTITY_INSERT mydb.DTreeNotify2 ON
INSERT INTO mydb.DTreeNotify2
(NID,NType,DataID,VersionNum,OwnerID,SubType)
SELECT inserted.NID,
inserted.NType,
inserted.DataID,
inserted.VersionNum,
mydb.Dtree.OwnerID,
livelink.DTree.SubType
FROM inserted, livelink.DTree
WHERE inserted.DataID = livelink.DTree.DataID;
END
I think ##rowcount becomes sql%rowcount, but I'm struggling with the identity_insert bit.
I don't think anything else should change. Opinions?
Don't worry about the IDENTITY_INSERT bit, the way it is done in Oracle is so much different that there is no need for such an option anyway. Look for "SEQUENCE" to learn more about that.
Here we go:
CREATE trigger "CONNECTERTRIGGER"
AFTER INSERT on "DtreeNotify"
FOR EACH ROW
begin
insert into DTreeNotify2 (NID,NType,DataID,VersionNum,OwnerID,SubType)
select :new.NID, :new.NType, :new.DataID, :new.VersionNum,
Dtree.OwnerID, livelink.DTree.SubType
from livelink.DTree
where :new.DataID=livelink.DTree.DataID;
end;
Comments: I assume Dtree.OwnerID is a package variable you can read directly.
As you can see, there is a :new record, which contains one inserted record (this trigger is called for each record that gets inserted).
Edit: changed the BEFORE trigger to an AFTER trigger
Related
I am trying to create SQL trigger which adds a new record to the same table where an insertion is made through a web page. I am not exactly sure how to implement it but I tried the following query
CREATE trigger [dbo].[trgI_DealsDoneInserRecord]
on [dbo].[Terms]
after insert
As
Insert into DealsDone
(Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product)
VALUES
(SELECT Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product FROM inserted)
END
The above query threw an error in the SELECT statement in VALUES.
May I know a way to implement this?
Try this:
CREATE trigger [dbo].[trgI_DealsDoneInserRecord]
ON [dbo].[Terms]
AFTER INSERT
As
BEGIN
INSERT INTO DealsDone
(Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product)
SELECT Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product FROM inserted
END
While I generally advocate against using SELECT *, in this case it seems like a benefit:
By not specifying the fields you can automatically account for changes in the tables without having to update this trigger if you add or remove or even rename fields.
This will help you catch errors in schema updates if one of the tables is updated but the other one isn't and the structure is then different. If that happens, the INSERT operation will fail and you don't have to worry about cleaning up bad data.
So use this:
CREATE TRIGGER [dbo].[trgI_DealsDoneInserRecord]
ON [dbo].[Terms]
AFTER INSERT
AS
SET NOCOUNT ON;
INSERT INTO [DealsDone]
SELECT *
FROM inserted;
There is an syntax issue, and also you are missing BEGIN
The basic syntax is
INSERT INTO table2 (column_name(s))
SELECT column_name(s)
FROM table1;
So try this
CREATE trigger [dbo].[trgI_DealsDoneInserRecord]
on [dbo].[Terms]
after insert
As
BEGIN
Insert into DealsDone
(Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product)
SELECT Company,Grade,Term,Pipeline,[Index],Volume,Price,[Type],CounterParty,
TermID,GradeID,CPID,Locked,Product
FROM inserted
END
Refer:- http://technet.microsoft.com/en-us/library/ms188263(v=sql.105).aspx
I have two databses, tempdblog and testdblog. I'm trying to figure out how, when i alter a table on tempdblog, that exact same command will be executed on testdblog, i don't want the rows transfered i strictly want the columns.
Below is what i have atm from a site, i've tried to add a "USE testdblog" but it errors back at me about "a USE statement is not allowed..." as well as "must declare the scalar variable #test".
The new column names could be anything, all i know is that it's not a "add this column to the end of the table", it's more like "add this column just before userdef0 column".
I store the SQL query it ran on the main database and try to re-execute it on the other table, it's just a matter of finding out how to change databases.
USE tempdblog
GO
ALTER TRIGGER [db_LOG]
ON DATABASE
FOR ALTER_TABLE
AS
SET NOCOUNT ON
DECLARE #xEvent XML
DECLARE #tests nvarchar(MAX)
SET #xEvent = eventdata()
SET #tests = CONVERT(VARCHAR(MAX), #xEvent.query('data(/EVENT_INSTANCE/TSQLCommand/CommandText)'))
exec testdblog..sp_executesql #tests;
GO
You can't have GO commands in there. Once you have a valid dynamic SQL statement constructed (you don't right now), you should also try:
EXEC testdblog..sp_executesql #test;
Or just simply:
INSERT INTO testdblog.dbo.dbLog(columns) VALUES(...);
Here is one very interesting problem. I am using SQL Server 2008.
I have two triggers on one common table say 'CommonTable'. one trigger is on update and other one is on insert/update/delete.
In first trigger "Trigger1", I do the checks/rollback sometime change the new inserted value based on business logic.
here is sample code
-
CREATE TRIGGER [dbo].[Trigger1] ON [dbo].[CommonTable]
FOR UPDATE
UPDATE [CommonTable]
SET
[StatusCode] = 'New Value'
WHERE
[RecId] = 'rec id value'
In second trigger "Trigger2", I store the new inserted/deleted/updated value from 'CommonTable' table to another table 'CommonTable_History' for history tracking purpose.
here is sample code
-
CREATE TRIGGER [dbo].[Trigger2] ON [dbo].[CommonTable]
FOR INSERT, UPDATE, DELETE
--based on logic read the value from DELETED or INSERTED table and store in other table.
SELECT #RowData = (SELECT * FROM DELETED AS [CommonTable] WHERE [RecId] = #RowRecId FOR XML AUTO, BINARY BASE64 , ELEMENTS)
--and then insert #RowData in 'CommonTable_History' table.
With the help of 'sp_settriggerorder', I have set the order of execution of these triggers, so first "Trigger1" get executed and then "Trigger2".
Second trigger "Trigger2" works well for insert/delete values. It works fine for new inserted value if new inserted values has not been changed by first trigger "Trigger1".
But if in some cases, inserted values has been changed in "Trigger1". say [StatusCode] = 'New Value' and old values was 'Old Value' then "Trigger2" still store the 'Old Value' instead of 'New Value'.
Why because "Trigger1" change the value but that value still has not been store in database and before that "Trigger2" get executed on Insert.
Now my requirement is, here I want to store "New Value".
So I thought, lets make "Trigger2" to use "AFTER" keywords. But "FOR" and "AFTER" behave same could not solve the problem.
Then I thought, lets make "Trigger2" to use "INSTEAD OF" keyword. But "INSTEAD OF" gives following error
"Cannot CREATE INSTEAD OF DELETE or INSTEAD OF UPDATE TRIGGER. This is because the table has a FOREIGN KEY with cascading DELETE or UPDATE."
I can not remove FOREIGN KEY with cascading DELETE or UPDATE for table 'CommonTable'.
Please let me know if you people have any other alternate solution.
-Vikram Gehlot
I think your second trigger needs to use the values from the actual table, not the inserted/deleted tables to populate the log table - inserted/deleted will always have the unaltered, original values, while your altered values will appear in the table. Make the second trigger an "After" trigger, so you will not have to use the sp_settriggerorder. Like this, for example:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER [dbo].[trg_Trig1]
ON [dbo].[TestTable]
FOR INSERT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
update TestTable
set [value] = 10
where [value] = 25
END
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER [dbo].[trg_Trig2]
ON [dbo].[TestTable]
AFTER INSERT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- Insert statements for trigger here
insert into log_TestTable
(id, description, [value])
select tt.id, tt.description, tt.[value]
from inserted i
LEFT JOIN TestTable tt
ON tt.id = i.id
END
It may not be the cleanest solution but can you simply combine the two triggers into one? That way both pieces of SQL would know about each other's changes.
Your second trigger appears to me as if it would not work properly is mulitple records are inserted in a set-based operations unloess you use a loop which is poor choice in a trigger. Fix that first!
Instead of select * from deleted, why not join the deleted or inserted table to the original table and take the values from there (except for the id value which you get from deleted or inserted, that should give you the most current values of all fileds and if you add other trigger logic later wil not break.
I'm using Sqlserver express and I can't do before updated trigger. There's a other way to do that?
MSSQL does not support BEFORE triggers. The closest you have is INSTEAD OF triggers but their behavior is different to that of BEFORE triggers in MySQL.
You can learn more about them here, and note that INSTEAD OF triggers "Specifies that the trigger is executed instead of the triggering SQL statement, thus overriding the actions of the triggering statements." Thus, actions on the update may not take place if the trigger is not properly written/handled. Cascading actions are also affected.
You may instead want to use a different approach to what you are trying to achieve.
It is true that there aren't "before triggers" in MSSQL. However, you could still track the changes that were made on the table, by using the "inserted" and "deleted" tables together. When an update causes the trigger to fire, the "inserted" table stores the new values and the "deleted" table stores the old values. Once having this info, you could relatively easy simulate the "before trigger" behaviour.
Can't be sure if this applied to SQL Server Express, but you can still access the "before" data even if your trigger is happening AFTER the update. You need to read the data from either the deleted or inserted table that is created on the fly when the table is changed. This is essentially what #Stamen says, but I still needed to explore further to understand that (helpful!) answer.
The deleted table stores copies of the affected rows during DELETE and
UPDATE statements. During the execution of a DELETE or UPDATE
statement, rows are deleted from the trigger table and transferred to
the deleted table...
The inserted table stores copies of the affected rows during INSERT
and UPDATE statements. During an insert or update transaction, new
rows are added to both the inserted table and the trigger table...
https://msdn.microsoft.com/en-us/library/ms191300.aspx
So you can create your trigger to read data from one of those tables, e.g.
CREATE TRIGGER <TriggerName> ON <TableName>
AFTER UPDATE
AS
BEGIN
INSERT INTO <HistoryTable> ( <columns...>, DateChanged )
SELECT <columns...>, getdate()
FROM deleted;
END;
My example is based on the one here:
http://www.seemoredata.com/en/showthread.php?134-Example-of-BEFORE-UPDATE-trigger-in-Sql-Server-good-for-Type-2-dimension-table-updates
sql-server triggers
T-SQL supports only AFTER and INSTEAD OF triggers, it does not feature a BEFORE trigger, as found in some other RDBMSs.
I believe you will want to use an INSTEAD OF trigger.
All "normal" triggers in SQL Server are "AFTER ..." triggers. There are no "BEFORE ..." triggers.
To do something before an update, check out INSTEAD OF UPDATE Triggers.
To do a BEFORE UPDATE in SQL Server I use a trick. I do a false update of the record (UPDATE Table SET Field = Field), in such way I get the previous image of the record.
Remember that when you use an instead trigger, it will not commit the insert unless you specifically tell it to in the trigger. Instead of really means do this instead of what you normally do, so none of the normal insert actions would happen.
Full example:
CREATE TRIGGER [dbo].[trig_020_Original_010_010_Gamechanger]
ON [dbo].[T_Original]
AFTER UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE #Old_Gamechanger int;
DECLARE #New_Gamechanger int;
-- Insert statements for trigger here
SELECT #Old_Gamechanger = Gamechanger from DELETED;
SELECT #New_Gamechanger = Gamechanger from INSERTED;
IF #Old_Gamechanger != #New_Gamechanger
BEGIN
INSERT INTO [dbo].T_History(ChangeDate, Reason, Callcenter_ID, Old_Gamechanger, New_Gamechanger)
SELECT GETDATE(), 'Time for a change', Callcenter_ID, #Old_Gamechanger, #New_Gamechanger
FROM deleted
;
END
END
The updated or deleted values are stored in DELETED. we can get it by the below method in trigger
Full example,
CREATE TRIGGER PRODUCT_UPDATE ON PRODUCTS
FOR UPDATE
AS
BEGIN
DECLARE #PRODUCT_NAME_OLD VARCHAR(100)
DECLARE #PRODUCT_NAME_NEW VARCHAR(100)
SELECT #PRODUCT_NAME_OLD = product_name from DELETED
SELECT #PRODUCT_NAME_NEW = product_name from INSERTED
END
I've got the following trigger on a table for a SQL Server 2008 database. It's recursing, so I need to stop it.
After I insert or update a record, I'm trying to simply update a single field on that table.
Here's the trigger :
ALTER TRIGGER [dbo].[tblMediaAfterInsertOrUpdate]
ON [dbo].[tblMedia]
BEFORE INSERT, UPDATE
AS
BEGIN
SET NOCOUNT ON
DECLARE #IdMedia INTEGER,
#NewSubject NVARCHAR(200)
SELECT #IdMedia = IdMedia, #NewSubject = Title
FROM INSERTED
-- Now update the unique subject field.
-- NOTE: dbo.CreateUniqueSubject is my own function.
-- It just does some string manipulation.
UPDATE tblMedia
SET UniqueTitle = dbo.CreateUniqueSubject(#NewSubject) +
CAST((IdMedia) AS VARCHAR(10))
WHERE tblMedia.IdMedia = #IdMedia
END
Can anyone tell me how I can prevent the trigger's insert from kicking off another trigger again?
Not sure if it is pertinent to the OP's question anymore, but in case you came here to find out how to prevent recursion or mutual recursion from happening in a trigger, you can test for this like so:
IF TRIGGER_NESTLEVEL() <= 1/*this update is not coming from some other trigger*/
MSDN link
I see three possibilities:
Disable trigger recursion:
This will prevent a trigger fired to call another trigger or calling itself again. To do this, execute this command:
ALTER DATABASE MyDataBase SET RECURSIVE_TRIGGERS OFF
GO
Use a trigger INSTEAD OF UPDATE, INSERT
Using a INSTEAD OF trigger you can control any column being updated/inserted, and even replacing before calling the command.
Control the trigger by preventing using IF UPDATE
Testing the column will tell you with a reasonable accuracy if you trigger is calling itself. To do this use the IF UPDATE() clause like:
ALTER TRIGGER [dbo].[tblMediaAfterInsertOrUpdate]
ON [dbo].[tblMedia]
FOR INSERT, UPDATE
AS
BEGIN
SET NOCOUNT ON
DECLARE #IdMedia INTEGER,
#NewSubject NVARCHAR(200)
IF UPDATE(UniqueTitle)
RETURN;
-- What is the new subject being inserted?
SELECT #IdMedia = IdMedia, #NewSubject = Title
FROM INSERTED
-- Now update the unique subject field.
-- NOTE: dbo.CreateUniqueSubject is my own function.
-- It just does some string manipulation.
UPDATE tblMedia
SET UniqueTitle = dbo.CreateUniqueSubject(#NewSubject) +
CAST((IdMedia) AS VARCHAR(10))
WHERE tblMedia.IdMedia = #IdMedia
END
TRIGGER_NESTLEVEL can be used to prevent recursion of a specific trigger, but it is important to pass the object id of the trigger into the function. Otherwise you will also prevent the trigger from firing when an insert or update is made by another trigger:
IF TRIGGER_NESTLEVEL(OBJECT_ID('dbo.mytrigger')) > 1
BEGIN
PRINT 'mytrigger exiting because TRIGGER_NESTLEVEL > 1 ';
RETURN;
END;
From MSDN:
When no parameters are specified, TRIGGER_NESTLEVEL returns the total
number of triggers on the call stack. This includes itself.
Reference:
Avoiding recursive triggers
ALTER DATABASE <dbname> SET RECURSIVE_TRIGGERS OFF
RECURSIVE_TRIGGERS { ON | OFF }
ON Recursive firing of AFTER triggers is allowed.
OFF Only direct recursive firing of AFTER triggers is not allowed. To
also disable indirect recursion of
AFTER triggers, set the nested
triggers server option to 0 by using
sp_configure.
Only direct recursion is prevented when RECURSIVE_TRIGGERS is set to OFF.
To disable indirect recursion, you
must also set the nested triggers
server option to 0.
The status of this option can be determined by examining the
is_recursive_triggers_on column in the
sys.databases catalog view or the
IsRecursiveTriggersEnabled property of
the DATABASEPROPERTYEX function.
I think i got it :)
When the title is getting 'updated' (read: inserted or updated), then update the unique subject. When the trigger gets ran a second time, the uniquesubject field is getting updated, so it stop and leaves the trigger.
Also, i've made it handle MULTIPLE rows that get changed -> I always forget about this with triggers.
ALTER TRIGGER [dbo].[tblMediaAfterInsert]
ON [dbo].[tblMedia]
FOR INSERT, UPDATE
AS
BEGIN
SET NOCOUNT ON
-- If the Title is getting inserted OR updated then update the unique subject.
IF UPDATE(Title) BEGIN
-- Now update all the unique subject fields that have been inserted or updated.
UPDATE tblMedia
SET UniqueTitle = dbo.CreateUniqueSubject(b.Title) +
CAST((b.IdMedia) AS VARCHAR(10))
FROM tblMedia a
INNER JOIN INSERTED b on a.IdMedia = b.IdMedia
END
END
You can have a separate NULLABLE column indicating whether the UniqueTitle was set.
Set it to true value in a trigger, and have the trigger do nothing if it's value is true in "INSERTED"
For completeness sake, I will add a few things. If you have a particular after trigger that you only want to run once, you can set it up to run last using sp_settriggerorder.
I would also consider if it might not be best to combine the triggers that are doing the recursion into one trigger.