O.F.,
So I have been attempting to build a trigger that will update a table based on the when a a row is updated in a different table. The trigger so far looks like this.
ALTER TRIGGER [dbo].[tst_update_USCATVLS_6]
ON [dbo].[IV00101]
AFTER UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE #ITEMNUMBER VARCHAR(75)
SET #ITEMNUMBER = (SELECT ITEMNMBR FROM dbo.IV00101 WHERE DEX_ROW_TS = (SELECT MAX(DEX_ROW_TS) FROM dbo.IV00101))
UPDATE dbo.EXT00101 SET STRGA255 = (RTRIM(LTRIM(STRGA255))) + '_0' WHERE PT_UD_KEY = #ITEMNUMBER AND PT_UD_Number = 2
What seems to happen when I run the test update like the one below.
UPDATE PDM.TEST.dbo.IV00101
SET USCATVLS_6 = 'OBSOLETE'
WHERE ITEMNMBR = 'HMLGDN-7563252-4'
Is that the trigger fires but updates the desired column twice. The end result being this 20025947756319_0_0 instead of this 20025947756319_0.
The weird part of all of this is if I drop the trigger and run the same test update and then run the update statement that was in the trigger all statements execute and the data is updated as desired.
So running this as one block of code works:
UPDATE PDM.TEST.dbo.IV00101
SET USCATVLS_6 = 'OBSOLETE'
WHERE ITEMNMBR = 'HMLGDN-7563252-4'
DECLARE #ITEMNUMBER VARCHAR(75)
SET #ITEMNUMBER = (SELECT ITEMNMBR FROM PDM.TEST.dbo.IV00101 WHERE DEX_ROW_TS = (SELECT MAX(DEX_ROW_TS) FROM PDM.TEST.dbo.IV00101))
UPDATE PDM.TEST.dbo.EXT00101 SET STRGA255 = (RTRIM(LTRIM(STRGA255))) + '_0' WHERE PT_UD_KEY = #ITEMNUMBER AND PT_UD_Number = 2
If any one can help me figure out why this is happening I would greatly appreciate it.
Kindest regards,
Z.
Having read Sean Lange's Comments I looked up inserted and deleted tables. I saw reference to these tables before but didn't realize they were temporary tables and thought they were physical tables of the database in the example/answers I saw. Anyway I created a trigger to show the data in each which helped me see how to join them to the update statement in the trigger. All the code is below.
Trigger to see what was in Inserted and Deleted as well as the join referencing the Inserted table:
ALTER TRIGGER [dbo].[inserted_deleted_Table]
ON [dbo].[IV00101]
AFTER UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
select 'NEW DATA', * from inserted --new data
select 'OLD Data', * from deleted --old data
select 'iv00101', * From iv00101 as i JOIN inserted as u on i.itemNmbr = u.itemNmbr and i.DEX_ROW_TS = u.DEX_ROW_TS
-- Insert statements for trigger here
END
The end solution was to remove this peice of code:
SET #ITEMNUMBER = (SELECT ITEMNMBR FROM INV00101 WHERE DEX_ROW_TS = (SELECT MAX(DEX_ROW_TS) FROM INV00101 ) AND USCATVLS_6 ='OBSOLETE' )
And then Add a the FROM clause to the UPDATE Statement:
UPDATE PDM.TEST.dbo.EXT00101 SET STRGA255 = (RTRIM(LTRIM(STRGA255))) + '_0'
FROM (
SELECT u.ITEMNMBR ,
u.DEX_ROW_TS
From iv00101 as i JOIN inserted as u on i.itemNmbr = u.itemNmbr and i.DEX_ROW_TS = u.DEX_ROW_TS) as p
WHERE PT_UD_KEY = p.ITEMNMBR AND PT_UD_Number = 2
Once I figured out that insert and deleted table were temp tables not actual tables in a DB all the pieces sorta fell into place. Thanks for pointing me in the direction I needed to go #Sean Lange.
Best Regards,
Z.
Related
I am trying to write an update trigger on a table which would cause it to run an additional update statement only if a certain column has been changed, so far the trigger runs the update no matter what, hoping maybe someone can see what I am doing wrong here.
Here is the trigger.
ALTER TRIGGER [dbo].[StatusChangedUpdateTrigger]
ON [dbo].[Trans_Order]
AFTER UPDATE
AS
DECLARE #OldOrderStatusId INT, #NewStatusOrderId INT, #ERRNUM INT;
BEGIN
SET #OldOrderStatusId = (SELECT OrderStatusId FROM deleted);
SET #NewStatusOrderId = (SELECT OrderStatusId FROM inserted);
IF (#OldOrderStatusId != #NewStatusOrderId)
SET NOCOUNT ON;
UPDATE Trans_Order
SET StatusChanged = 1
WHERE Id = (SELECT ID FROM inserted)
END
For some reason this is running no matter what, I can never set StatusChanged to 0 as it will automatically flip it back to 1 even if the OrderStatusId hasn't changed. So my update statement is running no matter what, so I am guessing I am doing something wrong in the if statement.
Hmmmm . . . Your logic seems strange. I would expect:
UPDATE t
SET StatusChanged = 1
FROM Trans_Order t JOIN
Inserted i
ON t.id = i.id JOIN
Deleted d
ON t.id = d.id
WHERE i.OrderStatusId <> d.OrderStatusId;
You might need to take NULL values into account -- although your code does not.
Note that your code is just a bug waiting to happen, because it assumes that inserted and deleted have only one row.
The specific problem with your code is that it is really:
IF (#OldOrderStatusId != #NewStatusOrderId)
BEGIN
SET NOCOUNT ON;
END;
UPDATE Trans_Order
SET StatusChanged = 1
WHERE Id = (SELECT ID FROM inserted);
Your indentation has confused the logic. However, you should still use the set-based version so the trigger does not fail.
The correct way to approach your trigger is as follows:
create or alter trigger [dbo].[StatusChangedUpdateTrigger] on [dbo].[Trans_Order]
after update
as
set nocount on
if ##RowCount=0 return
if Update(OrderStatusId)
begin
update t
set statusChanged=1
from inserted i join deleted d on d.id=i.id and d.OrderStatusId != i.OrderStatusId
join Trans_Order t on t.id=i.id
end
Always test ##rowcount and return if no rows updated.
Always put set options before DML
As you are only looking to update if a specific column is updated you can test specifically for that and if the update statement that's run doesn't touch that column the trigger will not run.
This will correctly account for multiple rows being updated and only update those where the new value is different to the old value.
I have 2 tables mpayment and account. When someone updates data in mpayment, then the trigger should automatically update the account table with the newly updated data. I wrote this trigger on my mpayment table, but when I try to update some data, I get an error:
The row value update or deleted either do make the row unique or they alter multiplerows [2 rows]
This is my trigger that I am trying to use
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER TRIGGER [dbo].[mpacupdate]
ON [dbo].[mpayment]
AFTER UPDATE
AS
BEGIN
DECLARE #pid AS NCHAR(10)
DECLARE #memid AS NCHAR(10)
DECLARE #pdate AS DATE
DECLARE #pamount AS MONEY
DECLARE #flag AS INT
SELECT #pid = list.pid FROM inserted list;
SELECT #memid = list.memid FROM inserted list;
SELECT #pdate = list.pdate FROM inserted list;
SELECT #pamount = list.pamount FROM inserted list;
SELECT #flag = list.flag FROM inserted list;
BEGIN
UPDATE [dbo].[account]
SET memid = #memid, pdate = #pdate,
pamount = #pamount, flag = #flag
WHERE pid = #pid
END
END
Your trigger is assuming that only 1 row will be updating at a time; it shouldn't. Treat the data as what it is, a dataset (not a set a scalar values).
This maynot fix the problem, as there's no sample data here to test against. I'm also not really sure that what you're after here is the right design choice, however, there's no information on what that is. Generally, you shouldn't be repeating data across tables; if you need data from another table then use a JOIN, don't INSERT or UPDATE both. If they become out of sync you'll start to get some really odd results I imagine.
Anyway, on track, this is probably what you're looking for, however, please consider the comments I've made above:
ALTER TRIGGER [dbo].[mpacupdate] ON [dbo].[mpayment]
AFTER UPDATE
AS BEGIN
UPDATE A
SET memid = i.memid,
pdate = i.pdate,
pamount = i.pamount,
flag = i.flag
FROM dbo.Account A
JOIN inserted i ON A.pid = i.pid;
END
I have this delete trigger on an SQL database. The record deletes currently and gets written to an audit table. I have been asked to include in this history table a field from another table that is related to the record being deleted based on SurveyID. I thought I could do something like
select #Status = Status from table where Survey = deleted.Survey
But this is incorrect syntax.
ALTER trigger [dbo].[table_Selfdelete]
on [dbo].[table]
after delete
as
Begin
Set nocount on;
Declare #SurveyId int
Declare #StudentUIC varchar(10)
Declare #Status varchar(10)
select #SurveyId = deleted.SurveyID,
#StudentUIC = deleted.StudentUIC
from deleted
select #Status = Status from tbly when SurveyID = deleted.SurveyID
insert into fupSurveyAudit
values(#SurveyId,#StudentUIC,#Status)
End
Arrgh. I think you want this insert in your trigger (and nothing else):
insert into fupSurveyAudit(SurveyId, StudentUIC, status)
select d.SurveyId, d.StudentUIC, y.status
from deleted d left join
tbly y
on d.SurveyId = y.SurveyId;
Notes:
deleted could contain more than one row, so assuming that it has one row can lead to a run-time error or incorrect results.
A left join is needed in case there is no matching row for the status.
You should always include the columns in an insert
Your archive table should have additional columns, such as an identity column and the date of the insert, which are set automatically (and hence not explicitly part of the insert).
Triggers are fired once for each statement (Delete,insert,update) not for each row inside the statement.
You cannot use variables here because when multiple lines are deleted from the table only one line will be inserted in the Audit table because the variable can only hold one value.
You just need a simple insert from the deleted table into the Audit table something like this....
ALTER trigger [dbo].[table_Selfdelete]
on [dbo].[table]
after delete
as
Begin
Set nocount on;
insert into fupSurveyAudit(SurveyId, StudentUIC,[Status])
select d.SurveyID
,d.StudentUIC
,y.[Status]
from deleted d
INNER JOIN tbly y ON y.SurveyID = deleted.SurveyID
End
Try this
ALTER trigger [dbo].[table_Selfdelete]
on [dbo].[table]
after delete
as
Begin
Set nocount on;
insert into fupSurveyAudit -- Better listed the column list here
select
d.SurveyID, d.StudentUIC, y.Status
from
deleted d JOIN tbly y ON d.SurveyID = y.SurveyID
End
I have a small performance issue with one of my database triggers in my MS-SQL Server 2014 database.
CREATE TRIGGER [dbo].[TRG_T_TPM_Vehicle_Update] ON [dbo].[T_TPM_Vehicle]
AFTER UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
UPDATE T_TPM_Vehicle SET LastUpdated = getdate()
WHERE Vehicle_Number IN (SELECT Vehicle_Number FROM inserted)
UPDATE T_TPM_Vehicle SET [DisturbedSince] = getdate()
WHERE Vehicle_Number IN (SELECT Vehicle_Number FROM inserted WHERE inserted.Emergency_Stop = 1)
AND Vehicle_Number IN (SELECT Vehicle_Number FROM deleted WHERE deleted.Emergency_Stop = 0)
INSERT INTO T_TPM_Vehicle_HistoricalData
([Vehicle_Ref]
,[Vehicle_Number]
,[Vehicle_Type]
,[Pos_X]
,[Pos_Y]
,[Alpha]
,[LastAutoPos_X]
,[LastAutoPos_Y]
,[LastAutoAlpha]
,[Automatic]
,[Manual]
,[Blocked]
,[Loaded]
,[Stoped]
,[Emergency_Stop]
,[User_Required]
,[BatteryAlmostEmpty]
,[BatteryEmpty]
,[BatteryLevel]
,[ChargingRelaisEnable]
,[NavOK]
,[PowerOn]
,[Available]
,[OperatingMinutes]
,[UpdateOperatingMinutes]
,[DataChangedByVIS]
,[Blockingsreleased]
,[Cancelled]
,[ProductID]
,[HUIdent1]
,[HUIdent2]
,[HUType]
,[DisturbedSince])
SELECT inserted.[Vehicle_Ref]
,inserted.[Vehicle_Number]
,inserted.[Vehicle_Type]
,inserted.[Pos_X]
,inserted.[Pos_Y]
,inserted.[Alpha]
,inserted.[LastAutoPos_X]
,inserted.[LastAutoPos_Y]
,inserted.[LastAutoAlpha]
,inserted.[Automatic]
,inserted.[Manual]
,inserted.[Blocked]
,inserted.[Loaded]
,inserted.[Stoped]
,inserted.[Emergency_Stop]
,inserted.[User_Required]
,inserted.[BatteryAlmostEmpty]
,inserted.[BatteryEmpty]
,inserted.[BatteryLevel]
,inserted.[ChargingRelaisEnable]
,inserted.[NavOK]
,inserted.[PowerOn]
,inserted.[Available]
,inserted.[OperatingMinutes]
,inserted.[UpdateOperatingMinutes]
,inserted.[DataChangedByVIS]
,inserted.[Blockingsreleased]
,inserted.[Cancelled]
,inserted.[ProductID]
,inserted.[HUIdent1]
,inserted.[HUIdent2]
,inserted.[HUType]
,inserted.[DisturbedSince]
FROM inserted
END
What it basically does is it sets the LastUpdated column for all rows in inserted and the DisturbedSince column for a subset of the inserted rows.
Finally the inserted rows get copied to a history table. (Every change on any row must be saved for two days). Older data gets deleted by a maintenance job.
As we have up to ~ 300 rows updated per second (Updates to rows can be batched together) We create a big amount of data and recursive updates.
I've now found the INSTEAD OF UPDATE triggers which seem to solve the recursive UPDATE problem caused by my trigger but I would have to process every row of the inserted table one by one with an update statement in the trigger.
I'm not sure if this is really faster. Does anyone of you have a recommendation?
What I really need is to tweak / extend the data rows before they are send to the table. Is there an approach for this?
e.g.: Something like:
CREATE TRIGGER ... INSTEAD OF UPDATE
AS
BEGIN
UPDATE inserted SET LastUpdated = getdate()
UPDATE inserted SET DisturbedSince
WHERE Vehicle_Number IN (SELECT Vehicle_Number FROM inserted WHERE inserted.Emergency_Stop = 1)
AND Vehicle_Number IN (SELECT Vehicle_Number FROM deleted WHERE deleted.Emergency_Stop = 0)
"SAVE INSERTED"
END
and an AFTER UPDATE TRIGGER with the storage of the changed data to the history table.
Thank you for any suggestions.
Thomas
You're right to think that using an INSTEAD OF trigger is the right way to go rather than an AFTER trigger, when you're wanting to change data within the same table as well.
It would be something like:
CREATE TRIGGER [dbo].[TRG_T_TPM_Vehicle_Update] ON [dbo].[T_TPM_Vehicle]
INSTEAD OF UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
UPDATE tgt
SET
Vehicle_Ref = i.Vehicle_Ref,
Vehicle_Type = i.Vehicle_Type,
...
LastUpdated = getdate(),
DisturbedSince = CASE WHEN i.Emergency_Stop=1 and d.Emergency_Stop=0
THEN getdate() ELSE d.DisturbedSince END
OUTPUT
inserted.[Vehicle_Ref]
,inserted.[Vehicle_Number]
,inserted.[Vehicle_Type]
...
,inserted.[HUIdent2]
,inserted.[HUType]
,inserted.[DisturbedSince]
INTO T_TPM_Vehicle_HistoricalData
([Vehicle_Ref]
,[Vehicle_Number]
,[Vehicle_Type]
...
,[HUIdent2]
,[HUType]
,[DisturbedSince])
FROM
T_TPM_Vehcile tgt
inner join
inserted i
on
tgt.Vehicle_Number = i.Vehicle_Number
inner join
deleted d
on
tgt.Vehicle_Number = d.Vehicle_Number
You'll note that I've combined both the UPDATEs and the INSERT into the history table into a single compound statement.
You'll also note that it's slightly confusing because there are two inserteds in play here - the inserted as part of the trigger (aliased as i to sidestep some of the confusion) and the inserted as part of the OUTPUT clause.
I need help creating this trigger, any help will be appreciate it, I can't save this script, it's saying 'Invalid column name OfferId'. But I checked all the columns names and they are correct
CREATE TRIGGER dbo.OrderOffer_UpdatedUnits
ON dbo.OrderOffer
FOR UPDATE
AS
BEGIN
DECLARE #OfferId char(5) SET #OfferId = (Select OfferId From INSERTED i, OrderOffer a Where i.OrderOfferid = a.OrderOfferid);
DECLARE #UnitsAvailable int SET #UnitsAvailable = (Select SUM(UnitsAvailable) From dbo.Offer Where OfferId=#OfferId);
UPDATE dbo.OrderOffer SET dbo.UnitsAvailable = #UnitsAvailable
FROM INSERTED i, OrderOffer a
WHERE i.OrderOfferid = a.OrderOfferid
END
Try this:
CREATE TRIGGER dbo.OrderOffer_UpdatedUnits
ON dbo.OrderOffer
FOR UPDATE
AS
BEGIN
UPDATE a
SET dbo.UnitsAvailable =
(
Select SUM(b.UnitsAvailable)
From dbo.Offer b
Where b.OfferId = a.OfferId
)
FROM OrderOffer a
INNER JOIN INSERTED i
ON i.OrderOfferid = a.OrderOfferid
END
NB: I removed the variables since that would assume you only updated one row at a time. Even if the update runs over multiple rows, the above should still work.