I have a trigger on a table that is something like this:
ALTER TRIGGER [shoot_sms]
ON [dbo].[MyTable]
AFTER INSERT
AS
begin
declare #number bigint
declare #body varchar(50)
declare #flag int
select #number=number,#body=body,#flag=flag from inserted
if(#flag=0)
begin
insert into temptable (number,body,status)
select #number,#body,'P'
end
end
Now I am making two entries in mytable as below:
insert into mytable(number, body, flag)
values(3018440225, 'This is test', 0)
insert into mytable(number, body, flag)
values(3018440225, 'This is test', 0)
I execute these queries at a time, but for both of the queries the trigger fires only once and performs the task for the first query only.
How can I make it work for both insert statements?
Just an idea but put a GO statement between those two insert statements and that might cause the trigger to fire twice.
You should probably rewrite your trigger to handle multiple row inserts I think.
Here is your query converted. You should get two rows now.
ALTER TRIGGER [shoot_sms]
ON [dbo].[MyTable]
AFTER INSERT
AS
begin
insert into temptable (number,body,status)
select number,body,'P'
from inserted
where flag = 0
end
Also notice your trigger is much simpler now.
Since those two statements are in one SQL batch, the trigger will (by design) only fire once.
Triggers don't fire once per row - they fire once per statement! So if you have an INSERT or UPDATE statement that affects more than one row, your trigger will have more than one row in the Inserted (and possibly Deleted) pseudo tables.
The way you wrote this trigger is really not taking into account that Inserted could contain multiple rows - what row do you select from the Inserted table if you're inserting 20 rows at once?
select #number = number, #body = body, #flag = flag from inserted
You need to change your trigger to take that into account!
Related
I have to create query that after delete will insert data in other table. But I've deleted 3 rows in my table, but table with insert has only one row. And it's the first row that was deleted.
This is my trigger:
CREATE trigger trigger1
ON Sales.SalesPerson
FOR DELETE
AS
BEGIN
DECLARE #ID int
SELECT #ID = BusinessEntityID FROM deleted
INSERT INTO dbo.Deleted(ID)
VALUES (#ID)
PRINT 'TRIGGER'
END
What did I do wrong?
In SQL Server, triggers fire per operation, not per row.
If you delete three rows, your SELECT assignment is going to (at least logically) assign each of those three values to the variable one at a time, and so the value that ultimately ends up in your logging table is the arbitrary value that happened to be assigned last.
You can simulate this as follows:
DECLARE #id int;
SELECT #id = database_id FROM sys.databases;
PRINT #id;
There are multiple rows in sys.databases, why did only one value get printed?
Instead of using a scalar variable and expecting it to somehow hold multiple values (or for the insert to happen multiple times), you need to insert as a set in a single operation:
INSERT dbo.Deleted(ID)
SELECT BusinessEntityID from deleted;
Further reading.
I am trying to accomplish the following 3 simple tasks as a transaction (i.e. I need to lock old_table and new_table until the process completes).
Create a new table (new_table)
Add a trigger to old_table, which queues updates to new_table.
Select all the data from old_table and return it.
Note that I want these handled in a single transaction. I cannot allow inserts into old_table (and therefore triggered inserts into new_table) in between the trigger creation and the select on old_table.
My current closest attempt is this, but truthfully I feel that I am very far off from accomplishing my goal with this code. I have added the code just for reference of what I am trying, but I am mostly interested in non-specific answers that layout how to accomplish the above three comands in a transaction.
DROP PROCEDURE IF EXISTS dbo.BuildAll;
CREATE PROCEDURE dbo.BuildAll
AS
BEGIN
BEGIN TRANSACTION
DECLARE #TriggerCode VARCHAR(MAX)
CREATE TABLE dbo.new_table
(
status nvarchar(5),
type char(1),
col1 nvarchar(50),
col2 smallint
)
SELECT #TriggerCode = 'CREATE TRIGGER myTrigger
ON dbo.old_table FOR INSERT
AS
DECLARE #col1_new nvarchar(50)
DECLARE #col2_new smallint
SELECT #col1_new = col1 FROM inserted
SELECT #col2_new = col2 FROM inserted
IF #col1_new IS NOT NULL
BEGIN
INSERT INTO new_table (status, type, col1, col2)
SELECt "Q", "A", #col1, #col2 FROM inserted
END'
EXEC(#TriggerCode)
SELECT * FROM old_table
COMMIT
END
Going to suggest this an a possible solution you can try. This doesn't address the correctness of your actual trigger, you have two separate questions here really.
You don't need to encapsulate this entire process in a transaction.
Create your new table.
Create your trigger on old table, but disabled.
set transaction isolation level serializable
begin tran
go
create trigger <Name> on <Table> etc
go
disable trigger <Name> on <Table>
go
commit
Now in a transaction you can lock the old table against other activity while you work
begin tran
update oldtable with(tablockx) set column=column where id=0 /* block other processes from updating table, id=0 row doesn't exist */
query your data and process as required
enable trigger <Name> on <Table>
commit
This trigger code of yours is kinda odd .... you have a trigger on all three operations - yet it appears as if you're never using the values you fetch from the deleted pseudo table, and if the value from the inserted table is NULL, you're not doing anything inside your trigger - so you can really spare yourself the DELETE case - that'll never do anything....
Also, as mentioned in my comment - you Inserted pseudo table can easily contain multiple rows - but you're selecting from it as if you only ever expect it to contain a single row.
You should really rewrite your trigger code to handle the case of multiple rows in Inserted and make the whole thing properly set-based - something like this:
CREATE TRIGGER myTrigger
ON dbo.old_table
FOR INSERT, UPDATE
AS
INSERT INTO new_table (status, type, col1, col2)
SELECT 'Q', 'A', i.col1, i.col2
FROM Inserted i
Whether you need this on the UPDATE case at all - I cannot tell, you need to decide this. But basically: just select from the Inserted table, take the Col1 and Col2 values, and add the constant values 'Q' and 'A' to your insert to handle multiple rows properly. That should do it.
I need to update a column in table after any record is added in same table
Here is my sql code
CREATE TRIGGER [dbo].[EmployeeInsert]
ON [dbo].[APP_Employees]
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
DECLARE #EmployeeID AS bigint
SELECT #EmployeeID = ID FROM inserted
UPDATE [dbo].[APP_Employees]
SET [EmployeeTotalNumberOfAnnualLeave] = [EmployeeBalanceTheInitialNumberOfDaysOfAnnualLeaveIn]
WHERE ID=#EmployeeID
END
GO
and showing error
Msg 2714, Level 16, State 2, Procedure EmployeeInsert, Line 17
There is already an object named 'EmployeeInsert' in the database.
The error you're getting is because you have that trigger already, in your database. So if you want to create it again, you need to first drop the existing trigger (or use ALTER TRIGGER instead of CREATE TRIGGER to modify the existing trigger).
BUT: your fundamental flaw is that you seem to expect the trigger to be fired once per row - this is NOT the case in SQL Server. Instead, the trigger fires once per statement, and the pseudo table Inserted might contain multiple rows.
Given that that table might contain multiple rows - which one do you expect will be selected here??
SELECT #EmployeeID = ID FROM inserted
It's undefined - you might get the values from arbitrary rows in Inserted.
You need to rewrite your entire trigger with the knowledge the Inserted WILL contain multiple rows! You need to work with set-based operations - don't expect just a single row in Inserted !
-- drop the existing trigger
DROP TRIGGER [dbo].[EmployeeInsert]
GO
-- create a new trigger
CREATE TRIGGER [dbo].[EmployeeInsert]
ON [dbo].[APP_Employees]
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
-- update your table, using a set-based approach
-- from the "Inserted" pseudo table which CAN and WILL
-- contain multiple rows!
UPDATE [dbo].[APP_Employees]
SET [EmployeeTotalNumberOfAnnualLeave] = i.[EmployeeBalanceTheInitialNumberOfDaysOfAnnualLeaveIn]
FROM Inserted i
WHERE [dbo].[APP_Employees].ID = i.ID
END
GO
Problem: I wrote a trigger that is supposed to update the INVOICE table after an INSERT into the LINE table but it won't update the invoice table. The trigger fires but the Update statement block won't execute.
I debugged while I executed the INSERT into the line table and found out as soon as the it gets to the UPDATE statement it jumps over it and doesn't run that code. I have been trying to figure this out for a couple of days now.
Here is my trigger code
ALTER TRIGGER [dbo].[trgInvoiceInsert] ON [dbo].[LINE]
AFTER INSERT
AS
declare #linUnits numeric(9,2);
declare #linPrice numeric(9,2);
declare #invNum int;
select #linUnits = LINE_UNITS from inserted;
select #linPrice = LINE_PRICE from inserted;
select #invNum = INV_NUMBER from inserted;
BEGIN
UPDATE i --From here it jumps to the start of the next Update
SET INV_SUBTOTAL = INV_SUBTOTAL + (#linUnits * #linPrice)
FROM dbo.INVOICE as i
WHERE i.INV_NUMBER = #invNum
UPDATE i
SET INV_TOTAL = INV_SUBTOTAL + INV_TAX
FROM dbo.INVOICE as i
WHERE i.INV_NUMBER = #invNum
PRINT 'Trigger fired Successfully.'
END
Well, using a statement like this:
select #linUnits = LINE_UNITS from inserted;
indicates that you're assuming that the trigger fires per row - it does not.
SQL Server triggers are fired once per statement - so if your statement inserts multiple rows into the Line table, your trigger will fire once for the complete statement, but the Inserted pseudo table will contain multiple rows of data.
So you need to rewrite your trigger to take that into account - the Inserted table can (and will!) contain multiple rows - and your trigger code needs to deal with that.
I am trying to copy data from table "tb_A" to itself (with different primary key).
When "tb_A" table is insert new record, I have written a trigger to populate another table "tb_B" with one record.
I ran the following statement.
INSERT INTO [tb_A]
([NAME])
select top (20)[NAME] from [tb_A]
I was expected 20 new records in "tb_B". But I didn't.
Anyway I saw FIRE_TRIGGERS is using during bulk insert to overcome this issue.
is there is a any way to use it on inset statements too ? Please provide me example.
Gayan
Trigger code (copied from Gayan's comment to gbn's answer):
CREATE TRIGGER UpdatetbB ON [dbo].[tb_A] FOR INSERT
AS
DECLARE #AID as int
SELECT #AID = [ID] FROM inserted
INSERT INTO [tb_B]([IDA]) VALUES (#AID)
The reason your trigger did not work properly is because it is poorly designed. Triggers fire once for each insert even if you are inserting a million records. You havea trigger that makes the assumption it will owrk one record at a time. Anytime you set a value form inserted or deleted to a scalar variable the trigger is wrong and needs to be rewritten. Try something like this instead.
CREATE TRIGGER UpdatetbB ON [dbo].[tb_A] FOR INSERT
AS
INSERT INTO [tb_B]([IDA])
SELECT [ID] FROM inserted
FIRE_TRIGGERS is only for BULK INSERT (and bcp), not "standard" INSERT
I'd expect your trigger to look something like
CREATE TRIGGER TRG_tbA_I ON tb_A FOR INSERT
AS
SET NOCOUNT ON
INSERT tb_B (col1, col2, ...)
SELECT col1, col2, ... FROM INSERTED
GO
You use the special INSERTED table to get the list of new rows in tb_A, then INSERT from this into tb_B. This works for more than one row
If you add the trigger code then we can explain what went wrong.
Edit: your trigger will only read a single row (any row, no particular order) from INSERTED. It isn't set based like my rough example.