i try to use trigger , when i insert in table penduduk, then in table muda will insert too, actually this trigger is work, but this trigger become loop, when i insert (123) in penduduk, then insert again (1234) then the result will be (123,1234,123,1234) , am i right to use 'From penduduk' ? or i should use 'FROM inserted' ? cause when i use FROM inserted there is no result
my query like this
CREATE TRIGGER auto_muda
ON penduduk
FOR INSERT
AS
INSERT INTO muda (noktp,tgl_lahir)
SELECT noktp, tgl_lahir FROM penduduk
WHERE umur < 27
You are currently grabbing all matching rows from penduduk rather than the inserted logical table. You might change your trigger to the following:
CREATE TRIGGER auto_muda
ON penduduk
FOR INSERT
AS
INSERT INTO muda (noktp,tgl_lahir)
SELECT noktp, tgl_lahir FROM inserted -- Use inserted, not the base table
WHERE umur < 27
From MSDN:
DML triggers use the deleted and inserted logical (conceptual) tables. They are structurally similar to the table on which the trigger is defined, that is, the table on which the user action is tried. The deleted and inserted tables hold the old values or new values of the rows that may be changed by the user action.
Use
Select noktb, tgl_lahir from inserted
If you're interested in inserting based on the newly inserted data. Your select seems to be capable of returning many items as it stands, which explains the "looping"/duplication.
Related
I’m trying to create a trigger to change the value of a column in table B if it finds the information in a column in table A.
An example of my database is below:
[TableA],
itemID
[TableB],
itemID
itemInStock
Once a user creates an entry in Table A declaring an itemID, the trigger needs to change the TableB.itemInStock column to ‘Yes’
I’m still learning SQL so excuse me if I’ve missed something, let me know if you need any more info.
I understand there are better ways of doing this but I've been told I need to do this using a trigger.
I've attempted a few different things, but as it stands nothing is working, below is the current solution I have however this updates all itemInStock rows to 'Yes', where as I only want the ones to update where the TableB.itemID matches the itemID entered in TableA.
ALTER TRIGGER [itemAvailability] ON [dbo].[TableA] FOR
INSERT
AS
BEGIN
UPDATE [dbo].[TableB] set itemInStock = 'Yes' WHERE
TableB.itemID = itemID
END
Two problems -
you're not looking at the Inserted pseudo table which contains the
newly inserted rows
you're assuming the trigger is called once per row - this is not the
case, the trigger is called once per statement and the Inserted
pseudo table will contain multiple rows - and you need to deal with
that
So, your code should look like this -
ALTER TRIGGER [itemAvailability] ON [dbo].[TableA]
FOR INSERT
AS
UPDATE TB
SET itemInStock = 'Yes'
FROM [dbo].[TableB] TB JOIN inserted I
on TB.itemID = I.itemID
I have a table called dsReplicated.matDB and a column fee_earner. When that column is updated, I want to record two pieces of information:
dsReplicated.matDB.mt_code
dsReplicated.matDB.fee_earner
from the row where fee_earner has been updated.
I've got the basic syntax for doing something when the column is updated but need a hand with the above to get this over the line.
ALTER TRIGGER [dsReplicated].[tr_mfeModified]
ON [dsReplicated].[matdb]
AFTER UPDATE
AS
BEGIN
IF (UPDATE(fee_earner))
BEGIN
print 'Matter fee earner changed to '
END
END
The problem with triggers in SQL server is that they are called one per SQL statement - not once per row. So if your UPDATE statement updates 10 rows, your trigger is called once, and the Inserted and Deleted pseudo tables inside the trigger each contain 10 rows of data.
In order to see if fee_earner has changed, I'd recommend using this approach instead of the UPDATE() function:
ALTER TRIGGER [dsReplicated].[tr_mfeModified]
ON [dsReplicated].[matdb]
AFTER UPDATE
AS
BEGIN
-- I'm just *speculating* here what you want to do with that information - adapt as needed!
INSERT INTO dbo.AuditTable (Id, TriggerTimeStamp, Mt_Code, Old_Fee_Earner, New_Fee_Earner)
SELECT
i.PrimaryKey, SYSDATETIME(), i.Mt_Code, d.fee_earner, i.fee_earner
FROM Inserted i
-- use the two pseudo tables to detect if the column "fee_earner" has
-- changed with the UPDATE operation
INNER JOIN Deleted d ON i.PrimaryKey = d.PrimaryKey
AND d.fee_earner <> i.fee_earner
END
The Deleted pseudo table contains the values before the UPDATE - so that's why I take the d.fee_earner as the value for the Old_Fee_Earner column in the audit table.
The Inserted pseudo table contains the values after the UPDATE - so that's why I take the other values from that Inserted pseudo-table to insert into the audit table.
Note that you really must have an unchangeable primary key in that table in order for this trigger to work. This is a recommended best practice for any data table in SQL Server anyway.
Currently I have a Item table and a ItemWaste table.
Both tables will have some fields, such as: Name, Amount, etc. But the ItemWaste table will have one more field, which is the TimeWasted.
I wish to automatically insert the DELETED item from the Item table to the ItemWaste table, and at the same time insert the deletion time to the TimeWasted field.
I got no idea how to do this, is it using trigger???
Hope can get some help here... Appreciate any feedback... Thanks....
Sure - not a problem.
You need a basic AFTER DELETE trigger - something like this:
CREATE TRIGGER trg_ItemDelete
ON dbo.Item
AFTER DELETE
AS
INSERT INTO dbo.ItemWaste(Name, Amount, TimeWasted)
SELECT d.Name, d.Amount, GETDATE()
FROM Deleted d
That's all there is! One point to remember: the trigger is called once per batch - e.g. if you delete 100 rows at once, it will be called once and the pseudo table Deleted will contain 100 rows. The trigger is not called once per row (a common misconception).
Yes, simply by writting a trigger you can insert a row when an delete action is performed in another table, have a look at Triggers
I want to do some calculations when my table data is changed. However, I am updating my table manually and copy pasting about 3000 rows in once. That makes my trigger work 3000 times, but I want it to do the trigger only once.
Is there a way to do that ?
Thanks.
What's your statement?
If you have multiple inserts then it will fire for each insert you are running. If you want it to execute only once for multiple inserts you must:
Write your insert on a single statement such as insert into foo select * from bar
Your trigger can't be for each row
Other possibility might be:
Disable the trigger
Perform your insertions
Put the trigger code in a stored procedure
Run your stored procedure
If by 'manually' you mean you are copying and pasting into some User Interface tool (like an Access dataGrid) or something like that, then the tool may be issuing one insert statement per row, and in that case you are out of luck the database trigger will be executed once per insert statement. As other answers have mentioned, if you can insert the rows directly into the database, using a single insert statement, then the trigger will only fire once.
The issue is caused because you are manually pasting the 3000 rows. You really have 2 solutions. You can turn off the trigger by doing this:
ALTER TABLE tablename DISABLE TRIGGER ALL
-- do work here
ALTER TABLE tablename ENABLE TRIGGER ALL
and then run the contents of your trigger at then end or you can put your 3000 columns into a temp table and then insert them all at once. This will only setup 1 trigger. If this isn't enough please give us more info on what you are trying to do.
Your trigger will not fire 3000 times if you are modifying 3000 rows in a single statement. Your trigger will fire once and there will be 3000 rows in your virtual 'deleted' table.
If you are limited in how you can import the data into the system that does a single insert per row, I would suggest that you import data into an intermediate table then do the insert into the final table from the intermediate one.
There is a better way.
Re-link the tables that your trigger created or altered, compare them against what's expected to be changed or added and avoid the trigger with a simple WHERE clause.
eg - this trigger I use to INSERT a record, but only once based on a column value existing (#ack).
DECLARE #ack INT
SELECT #ack = (SELECT TOP 1 i.CUSTOM_BOOL_1 AS [agent_acknowledged] FROM inserted AS i)
IF #ack = 1
BEGIN
INSERT INTO TABLEA(
COLA, COLB, etc
)
SELECT
COLA, COLB, etc
from inserted as i
LEFT JOIN TABLEA AS chk --relink to the INSERT table to see if the record already exists
ON chk.COLA = i.COLA
AND chk.COLB = i.COLB
AND etc
WHERE chk.ID IS NULL --and here we say if NOT found, then continue to insert
END
I have a table in a SQL Server 2005 database with a trigger that is supposed to add a record to a different table whenever a new record is inserted. It seems to work fine, but if I execute an Insert Into on the master table that uses a subquery as the source of the values, the trigger only inserts one record in the other table, even though multiple records were added to the master. I want the trigger to fire for each new record added to the master table. Is that possible in 2005?
The insert I'm doing is:
INSERT INTO [tblMenuItems] ([ID], [MenuID], [SortOrder], [ItemReference], [MenuReference], [ConcurrencyID]) SELECT [ID], [MenuID], [SortOrder], [ItemReference], [MenuReference], [ConcurrencyID] FROM [IVEEtblMenuItems]
Here is what the trigger looks like:
CREATE TRIGGER [dbo].[tblMenuItemInsertSecurity] ON [dbo].[tblMenuItems]
FOR INSERT
AS
Declare #iRoleID int
Declare #iMenuItemID int
Select #iMenuItemID = [ID] from Inserted
DECLARE tblUserRoles CURSOR FASTFORWARD FOR SELECT [ID] from tblUserRoles
OPEN tblUserRoles
FETCH NEXT FROM tblUserRoles INTO #iRoleID
WHILE (##FetchStatus = 0)
BEGIN
INSERT INTO tblRestrictedMenuItems(
[RoleID],
[MenuItemID],
[RestrictLevel])
VALUES(
#iRoleID,
#iMenuItemID,
1)
FETCH NEXT FROM tblUserRoles INTO #iRoleID
END
CLOSE tblUserRoles
Deallocate tblUserRoles
Your trigger is only using the first row from 'Inserted'. This is a common misunderstanding when dealing with SQL triggers for the first time. The trigger fires per update not per row.
For example if you do the following:-
update products
set title = 'geoff de geoff'
this would update all the products, but a trigger on the product table would only fire once.
The Inserted 'table' you get in trigger would contain all the rows. You must either loop through Inserted with a cursor, or better join Inserted to the table you are updating.
Please lookup multi row consideration for triggers
What is with the cursor inside a trigger? Learn how to program set based, cursors are Evil in T-SQL and should only be used to defragment/update stats/other maintanance a bunch of tables
The trigger only fires once for each INSERT statment executed - not once for each record inserted.
In your trigger you can access the 'virtual' table called inserted for details of the records inserted.
ie:
SELECT COUNT(*) FROM inserted
Will return the number of inserted records.
I just want to second #Gordon Bell on his answer...
"Catch" the values the very moment they are being inserted. You do not really need the cursor in this situation (or maybe you have a reason?).
A simple TRIGGER might be all you need:
http://dbalink.wordpress.com/2008/06/20/how-to-sql-server-trigger-101/