I have a SP that INSERT INTO TBL_DOMAIN from TBL_STAGING, but first I want check table TBL_STAGING to make sure the table is not empty before I truncate table TBL_DOMAIN, if table TBL_STAGING got more than one record then proceed the truncate table TBL_DOMAIN then run the INSERT, ELSE message say the table TBL_STAGING is EMPTY and exit the SP. My goal is to make sure the table TBL_DOMAIN still have the data even is old. I'm very new SQL please help.
CREATE PROCEDURE [dbo].[SP_INSERT_ALL_DOMAIN]
WITH EXECUTE AS CALLER
AS
BEGIN
BEGIN TRANSACTION NT_ALL_DOMAIN
INSERT INTO TBL_DOMAIN
(DOMAIN_NAME,
DISTINGUISHED_NAME,
EMAIL_ADDR_I)
SELECT DOMAIN_NAME,
DISTINGUISHED_NAME,
EMAIL_ADDR_I
FROM TBL_STAGING
First you need to check if TBL_STAGING has data:
IF EXISTS (SELECT TOP 1 1 FROM TBL_STAGING)
BEGIN
BEGIN TRANSACTION NT_ALL_DOMAIN
INSERT INTO TBL_DOMAIN
(DOMAIN_NAME,
DISTINGUISHED_NAME,
EMAIL_ADDR_I)
SELECT DOMAIN_NAME,
DISTINGUISHED_NAME,
EMAIL_ADDR_I
FROM TBL_STAGING
COMMIT
END
ELSE
BEGIN
RETURN 'no data on table'
END
Related
DROP TRIGGER IF EXISTS N2Trigger
CREATE TRIGGER N2Trigger
ON dbo.Date
FOR INSERT, DELETE
AS
BEGIN
SELECT 'Inserted Datebase' as MESSAGE
SELECT 'Deleted Database' as MESSAGE
END
DELETE FROM dbo.[Date] WHERE ID = 1
Here is my code I just want when I use insert statement return 'Inserted Datebase' as MESSAGE
When I use delete statement return 'Deleted Database' as MESSAGE
The easiest way to check what action fired the trigger is to inspect the inserted and deleted pseudo-tables. If the trigger is only on DELETE/INSERT and not on update, then the logic is simply:
CREATE TRIGGER dbo.trFlarb ON dbo.flarb
FOR INSERT, DELETE
AS
BEGIN
IF EXISTS (SELECT 1 FROM inserted)
BEGIN
SELECT 'Inserted.';
END
IF EXISTS (SELECT 1 FROM deleted)
BEGIN
SELECT 'Deleted.';
END
END
Example db<>fiddle
Now, of course, Marc is right: triggers aren't for returning or printing output. This is just a demonstration that you can use those checks to then perform whatever logic you need to perform in the event of either action.
That said, if you have two distinctly different things you want to do depending on whether it's an insert or a delete, why not just create two separate triggers?
CREATE TRIGGER dbo.tr_I_Flarb ON dbo.flarb
FOR INSERT
AS
BEGIN
SELECT 'Inserted.';
END
GO
CREATE TRIGGER dbo.tr_D_Flarb ON dbo.flarb
FOR DELETE
AS
BEGIN
SELECT 'Deleted.';
END
GO
Note that SELECT will only "work" on your system if you haven't turned on the disallow results from triggers Server Configuration Option. Again, you should try to explain what you really want to do in the event of an insert or update, because the end goal can't be to print or return "Inserted" or "Deleted."
My objective is inserting the first insert, but not letting the second to pass, because NIC is duplicated. I don't know why, but it isn't letting the first one pass without having other NIC to compare if it already exists one equal.
I know I can prevent duplicates with "unique", but I was trying to do with a trigger :/
Create table Utentes
(
numUtente nchar(3),
Name nchar(40) not null,
NIC nchar(8) not null,
Constraint PK_Utente Primary Key(numUtente)
)
create trigger tr_Duplicate
on Utentes
after insert
as
declare #NIC nchar(8)
select #NIC = NIC from inserted
if exists(select * from Utentes where NIC = #NIC)
begin
print 'NIC already in database'
rollback
end
go
insert into Utentes (numUtente, Name, NIC)
values ('123', 'asd', '12345678')
insert into Utentes (numUtente, Name, NIC)
values ('124', 'asd', '12345678')
select * from Utentes
Result:
NIC already in database
Msg 3609, Level 16, State 1, Line 1392
The transaction ended in the trigger. The batch has been aborted.
You should really use a constraint. An "after insert" trigger will actually put the second row in the table . . . and hopefully no one is using NOLOCK for reading it.
In any case, you have to actually count the rows and look for multiple occurrences. It would be something like this:
Create trigger tr_Duplicate on Utentes after INSERT as
begin
if exists (select 1
from utentes u join
inserted i
on u.nic = i.nic
group by u.nic
having count(*) > 1
)
begin
print 'NIC already in database';
rollback;
end;
end;
With an instead of trigger, you would not add new rows into the table if one already exists:
create trigger tr_Duplicate on Utentes after INSERT as
begin
if exists (select 1
from utentes u join
inserted i
on u.nic = i.nic
)
begin
print 'NIC already in database';
rollback;
end;
else
begin
insert into utentes
select i.*
from inserted i;
end;
end;
I would second the sentiment against the use of triggers and would also suggest using UNIQUE constraints. In my humble opinion, I would rather search for a solution in the ETL layer, grouping records as they are inserted. With triggers you will get the aforementioned concurrency and consistency issues, as well as potentially swelling your tempdb or T-log if the table ever gets big enough to take some time to process.
For two tables A and B, I'd like to implement referential integrity such that in tables A a foreign key's value must present in table B, while in table B a primary key can only be deleted or modified if that value does not present in table A. My requirement is that I'd like to have table A, and B as variable, and apply the procedure to any arbitrary instances of tables. That is,
sp_referential_integrity_across_databases(A, B)
I have figured out how to do the referential integrity as triggers for a pair of particular tables. I wonder if it's feasible to write such stored procedure to save future effort?
My environment is Microsoft SQL Server 2017. The more portable the solution, the better.
Here are my crafted procedures:
The triggers on table "A" for insert and update:
USE DWPractice
IF OBJECT_ID ('dbo.trgCheckCustomer_Cat_Id_Customer_D', 'TR') IS NOT NULL
DROP Trigger trgCheckCustomer_Cat_Id_Customer_D;
GO
CREATE TRIGGER trgCheckCustomer_Cat_Id_Customer_D
ON Customer_D
AFTER INSERT, UPDATE
AS
IF NOT EXISTS
(
SELECT Customer_Cat_Id
FROM inserted
WHERE Customer_Cat_Id IN (SELECT Customer_Cat_Id FROM [OtherDW].[dbo].[Customer_Cat_D])
)
BEGIN
RAISERROR('Lookup Value Not Found -- Inerst Failed', 16, 1);
ROLLBACK TRANSACTION;
END;
The trigger on table "B" for delete and update:
USE OtherDW
IF OBJECT_ID ('dbo.trgCheckCustomer_Cat_Id_Customer_Cat_D', 'TR') IS NOT NULL
DROP Trigger trgCheckCustomer_Cat_Id_Customer_Cat_D;
GO
CREATE TRIGGER trgCheckCustomer_Cat_Id_Customer_Cat_D
ON Customer_Cat_D
AFTER DELETE, UPDATE
AS
Begin
IF EXISTS
(
SELECT Customer_Cat_Id
FROM deleted
WHERE Customer_Cat_Id IN (SELECT Customer_Cat_Id FROM [DWPractice].[dbo].[Customer_D])
)
BEGIN
RAISERROR('Lookup Value Found -- Delete Failed', 16, 1);
ROLLBACK TRANSACTION;
END;
-- It seems that the following for the case of update is not needed
-- The above clauses would get executed even for the case of update.
-- IF EXISTS
-- (
-- SELECT Customer_Cat_Id
-- FROM inserted
-- WHERE Customer_Cat_Id IN (SELECT Customer_Cat_Id FROM [DWPractice].[dbo].[Customer_D])
-- )
-- BEGIN
-- RAISERROR('Lookup Value Found -- Update Failed', 16, 1);
-- ROLLBACK TRANSACTION;
-- END;
End;
If stored procedure is not the best practice, then what is the best practice? It seems to me, there's much boiler-plate code, with only database name and table name are variables.
The logic in your (first) trigger is not correct. If you have multiple rows in inserted, then only one has to match. Instead, you want:
CREATE TRIGGER trgCheckCustomer_Cat_Id_Customer_D ON Customer_D AFTER INSERT, UPDATE
AS BEGIN
IF EXISTS (SELECT 1
FROM inserted i LEFT JOIN
[OtherDW].[dbo].[Customer_Cat_D] d
ON i.Customer_Cat_Id = d.Customer_Cat_Id
WHERE d.Customer_Cat_Id IS NULL
)
BEGIN
RAISERROR('Lookup Value Not Found -- Insert Failed', 16, 1);
ROLLBACK TRANSACTION;
END;
END; -- trigger
I have a trigger for auditing purchase and sales table. The trigger is on INSERT and DELETE. To check if its "Insert", the condition is
IF (SELECT COUNT(*) FROM INSERTED) > 0
BEGIN
END
How do I check if its an Update command inside the Trigger?
Arun
The "tables" that are in play in an update trigger are still called inserted and deleted, and the old values of the rows are in the deleted table, and the new values are in the inserted table.
You can use logic along these lines to detect whether you are in a insert, update or a delete:
CREATE TRIGGER MyTrigger
ON MyTable
AFTER INSERT,DELETE,UPDATE -- you need to add the "update" here,
-- in order to catch updates as well
AS
BEGIN
Declare #insertedCount int
Declare #deletedCount int
select #insertedCount = COUNT(*) from inserted
select #deletedCount = COUNT(*) from deleted
if (#insertedCount != 0) -- we have some new values
if (#deletedCount = 0) -- do we have old values?
print 'Inserting'
else
print 'Updating'
else
print 'Deleting'
END
An INSERT,DELETE trigger will not fire for updates.
.........................
CREATE an INSERT, UPDATE, DELETE all in one table
IF ##ROWCOUNT = 0
BEGIN
RETURN;
END;
IF EXISTS(SELECT * FROM inserted)
BEGIN
IF EXISTS(SELECT * FROM deleted)
BEGIN
-- for UPDATE
END
ELSE
BEGIN
-- for INSERT
END
END
ELSE
BEGIN
-- for DELETE
END;
Once you've updated your trigger (as Mitch says) to also apply to UPDATEs, you need to check for updates first:
IF EXISTS(select * from inserted) and EXISTS(select * from deleted)
BEGIN
--Update
END
Note that I've switch to EXISTS rather than COUNT(*). Exists more properly describes what we want to establish - that rows exist in the table. We don't care how many rows are in there.
I would like to thank "SWeko" for the clue.
Now, this what I did and the Trigger worked.
CREATE TRIGGER dbo.Sample
ON TableName
FOR INSERT, UPDATE, DELETE
AS
IF (SELECT COUNT(*) FROM INSERTED) > 0
BEGIN
IF (SELECT COUNT(*) FROM DELETED) > 0
BEGIN
-- UPDATE (TABLE).
END
ELSE
BEGIN
-- INSERT (TABLE).
END
END
ELSE
-- DELETE (TABLE).
BEGIN
END
I have two Tables.
I want to insert the same record on both tables at the same time.
I.e., while I insert a record for the first table, this same record also is inserted in the second table using a trigger.
Do you have any experience/advice in this process ?
if you're using stored procedures you can easily manage this
CREATE PROCEDURE sp_Insert
#Value varchar(10)
AS
insert into table1 (...,...) values (#value,...)
insert into table2 (...,...) values (#value,...)
I would suggest using Erik's method over a trigger. Triggers tend to cause performance issues, and a lot of times, you forget that the trigger exists, and get unexpected behavior. If you do want to use a trigger however, it will work. here is an example:
CREATE TRIGGER trgTest ON Test
FOR INSERT
AS
INSERT Test2
(Id, value)
SELECT Id, Value
FROM Inserted
Can Use Cursor Concept!
CREATE OR REPLACE TRIGGER bi_order
BEFORE INSERT
ON ord
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
WHEN (NEW.payment_type = 'CREDIT')
DECLARE
CURSOR cur_check_customer IS
SELECT 'x'
FROM customer
WHERE customer_id = :NEW.customer_id
AND credit_rating = 'POOR';
lv_temp_txt VARCHAR2(1);
lv_poor_credit_excep EXCEPTION;
BEGIN
OPEN cur_check_customer;
FETCH cur_check_customer INTO lv_temp_txt;
IF (cur_check_customer%FOUND) THEN
CLOSE cur_check_customer;
RAISE lv_poor_credit_excep;
ELSE
CLOSE cur_check_customer;
END IF;
EXCEPTION
WHEN lv_poor_credit_excep THEN
RAISE_APPLICATION_ERROR(-20111, 'Cannot process CREDIT ' ||
'order for a customer with a POOR credit rating.');
WHEN OTHERS THEN
RAISE_APPLICATION_ERROR(-20122, 'Unhandled error occurred in' ||
' BI_ORDER trigger for order#:' || TO_CHAR(:NEW.ORDER_ID));
END bi_order;