Can someone please help me converting this into SQL server trigger.
Create a trigger that will cause an error when an update occurs that would result in a salary increase greater than ten percent of the current salary.
CREATE TRIGGER RAISE_LIMIT
AFTER UPDATE OF SALARY ON EMPLOYEE
REFERENCING NEW AS N OLD AS O
FOR EACH ROW
WHEN (N.SALARY > 1.1 * O.SALARY)
SIGNAL SQLSTATE '75000' SET MESSAGE_TEXT='Salary increase>10%'
In SQL Server, every trigger only runs once per statement, not per row, and the pseudo-tables inserted and deleted contain, respectively, the new and old versions of the rows. You must join these on the primary key to match up the versions.
Remember that these tables may contain multiple or no rows. The UPDATE function can tell you if a column was present in the UPDATE command, it will not tell you whether any rows changed.
The trigger runs within the same transaction as the UPDATE, and an error will cause an immediate rollback of all rows. Do not attempt to rollback yourself, this will cause spurious transactional errors. Instead use THROW.
The docs are located here, you should consult them for further syntax.
CREATE TRIGGER RAISE_LIMIT ON EMPLOYEE
AFTER UPDATE
AS
IF (UPDATE(SALARY)
AND EXISTS (SELECT 1
FROM inserted i
JOIN deleted d ON d.ID = i.ID
WHERE i.SALARY > 1.1 * d.SALARY))
BEGIN
THROW 75000, N'Salary increase > 10%', 0;
END;
GO
Related
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.
I have a table called INVOICE which stores bill information about an order/orders, one of the columns in this table is a column named paid which is a type of bit. As its name indicates, this column indicates whether the specific order/orders bill is paid or not.
I have another table named RECEIPT, this table stores information about any payment processes for a specific invoice.
So every time user pay an amount for the specified invoice, a new receipt record is created.
Now What I'm trying to do is to create a trigger that updates the paid column in the INVOICE table and set it to 1. This update process should be triggered in case of that the sum of receipts that belong to the invoice is equal to the amount_due in the INVOICE table.
In other words, if invoice due amount= 100$
and the user paid 50$
then, late he paid the other 50$
The paid column in the INVOICE table should be set to 1 as the total payments are equal to the invoice due amount
This is the trigger I've created to achieve the above
CREATE TRIGGER tg_invoice_payment ON RECEIPT
AFTER INSERT
AS
BEGIN
UPDATE INVOICE
SET paid = 1
WHERE INVOICE.invoice_id = (SELECT inserted.invoice_id FROM inserted)
AND (SELECT SUM(RECEIPT.amount_paid)
FROM RECEIPT
JOIN inserted ON RECEIPT.receipt_id = inserted.receipt_id
WHERE RECEIPT.invoice_id = inserted.invoice_id) = (SELECT INVOICE.amount_due
FROM INVOICE
JOIN inserted ON INVOICE.invoice_id = inserted.invoice_id
WHERE INVOICE.invoice_id = inserted.invoice_id)
END;
it compiled successfully but at run time I've get the below error:
The target table 'RECEIPT' of the DML statement cannot have any enabled triggers if the statement contains an OUTPUT clause without INTO clause
I think personally that you should update the paid status outside the scope of triggers. If you perform an INSERT into RECEIPT, you can execute the UPDATE INVOICE ... statement right after that (inside a TRANSACTION of course). A lot cleaner and predictable that way.
As to the error you are getting it's hard to say what is causing that based on the information you gave us. Perhaps the TRIGGER is triggering other TRIGGERs that produce the error you are getting? The statement you provided simply doesn't have an OUTPUT statement.
In any case, the statement you provided is not written correctly (as Damien pointed out) because the inserted table can have multipe rows. This is a rewrite to correct at least that part:
CREATE TRIGGER tg_invoice_payment ON RECEIPT
AFTER INSERT
AS
BEGIN
UPDATE
INVOICE
SET
paid = 1
FROM
inserted AS ins
INNER JOIN INVOICE AS inv ON
inv.invoice_id=ins.invoice_id
WHERE
inv.amount_due=(
SELECT
SUM(r.amount_paid)
FROM
RECEIPT AS r
WHERE
r.receipt_id=ins.invoice_id
);
END;
But as I mentioned earlier you probably not be doing this from a TRIGGER. Execute this statement from your program right after any INSERT/UPDATE. Alternatively, write a Stored Procedure for inserting into RECEIPT and execute the UPDATE statement right after the INSERT.
I've been trying to find a solution to a very simple problem, but I just cant find out how to do it. I have two tables Transactions and Credit_Card.
Transactions
transid (PK), ccid (FK: to credit_card > ccid), amount, timestamp
Credit_Card
ccid (PK), Balance, creditlimit
I want to create a trigger so before someone inserts a transaction it checks that the transaction amount + the balance of the credit card does not go over the creditlimit and if it is, it rejects the insert.
"EDIT" The following code fixed my issue, big thanks to Dan Guzman for his contribution!
CREATE TRIGGER TR_transactions
ON transactions FOR INSERT, UPDATE
AS
IF EXISTS(
SELECT 1
FROM (
SELECT t.ccid, SUM(t.amount) AS amount
FROM inserted AS t
GROUP BY t.ccid) AS t
JOIN Credit_Card AS cc ON
cc.ccid = t.ccid
WHERE cc.creditlimit <= (t.amount + cc.balance)
)
BEGIN
RAISERROR('Credit limit exceeded', 16, 1);
ROLLBACK;
END;
If I understand correctly, you just need to check the credit limit against newly inserted/updated transactions. Keep in mind that a SQL Server trigger fires once per statement and a statement may affect multiple rows. The virtual inserted will have images of the affected rows. You can use this to limit the credit check to only the credit cards affected by the related transactions.
CREATE TRIGGER TR_transactions
ON transactions FOR INSERT, UPDATE
AS
IF EXISTS(
SELECT 1
FROM (
SELECT inserted.ccid, SUM(inserted.amount) AS amount
FROM inserted
GROUP BY inserted.ccid) AS t
JOIN Credit_Card AS cc ON
cc.ccid = t.ccid
WHERE cc.creditlimit <= (t.amount + cc.balance)
)
BEGIN
RAISERROR('Credit limit exceeded', 16, 1);
ROLLBACK;
END;
EDIT
I removed the t alias from the inserted table and qualified the columns with inserted instead to better indicate the source of the data. It's generally a good practice to qualify column names with the table name or alias in multi-table queries to avoid ambiguity.
The integers 16 and 1 in the RAISERROR statement specify the severity and state of the raised error. See the SQL Server Books Online reference for details. Severity 11 and greater raise an error, with severities in the 11 through 16 range indicating a user-correctable error.
you can try this.
ALTER trigger [dbo].[TrigerOnInsertPonches]
On [dbo].[CHECKINOUT]
After Insert
As
BEGIN
DECLARE #ccid int
,#amount money
you have to tell sql that the trigger is ofter insert,
then you can declare the using variable. declare
select #ccid=o.ccid from inserted o;
I think is the correct whey to catch the id.
then you can make the select filtiering from this value.
I hope this can be usefull
I have a SQL Server 2008 database that has a Trigger. This trigger is defined as follows:
CREATE TRIGGER [dbo].[Trigger_Car_Insert] ON [dbo].[Car] FOR INSERT
AS
UPDATE
[Lot]
SET
[TotalCars]=lotCars.TotalCars
FROM
[Lot] l JOIN (
SELECT
c.[LotID], COUNT(*) as 'TotalCars'
FROM
inserted i JOIN [Car] c ON i.[LotID]=c.[LotID]
WHERE
c.[IsSold]=0
GROUP BY
c.[LotID]
) lotCars ON l.[ID]=lotCars.[LotID]
This works well for inserting. However, when a car gets sold, the IsSold flag gets updated to true. When this happens, I want a trigger to update the "TotalCars" property on the Lot table. I know there is an "inserted" and "deleted" table to detect what was just inserted/deleted. However, I cannot figure out the equivalent for updating.
How do I do this on SQL Server 2008? Thank you!
There is no "updated table" in update trigger. The values before update statement are in "deleted" table and new values are in "inserted" table. You can check whether a specific column was updated or not by using COLUMNS_UPDATED function.
Here is a simple example: An Introduction to Triggers -- Part II
I'm looking for the best way to go about adding a constraint to a table that is effectively a unique index on the relationship between the record and the rest of the records in that table.
Imagine the following table describing the patrols of various guards (from the previous watchman scenario)
PK PatrolID Integer
FK GuardID Integer
Starts DateTime
Ends DateTime
We start with a constraint specifying that the start and end times must be logical:
Ends >= Starts
However I want to add another logical constraint: A specific guard (GuardID) cannot be in two places at the same time, meaning that for any record the period specified by Start/Ends should not overlap with the period defined for any other patrol by the same guard.
I can think of two ways of trying to approach this:
Create an INSTEAD OF INSERT trigger. This trigger would then use cursors to go through the INSERTED table, checking each record. If any record conflicted with an existing record, an error would be raised. The two problems I have with this approach are: I dislike using cursors in a modern version of SQL Server, and I'm not sure how to go about implimenting the same logic for UPDATEs. There may also be the complexity of records within INSERTED conflicting with each other.
The second, seemingly better, approach would be to create a CONSTRAINT that calls a user defined function, passing the PatrolID, GuardID, Starts and Ends. The function would then do a WHERE EXISTS query checking for any records that overlap the GuardID/Starts/Ends parameters that are not the original PatrolID record. However I'm not sure of what potential side effects this approach might have.
Is the second approach better? Does anyone see any pitfalls, such as when inserting/updating multiple rows at once (here I'm concerned because rows within that group could conflict, meaning the order they are "inserted" makes a difference). Is there a better way of doing this (such as some fancy INDEX trick?)
Use an after trigger to check that the overlap constraint has not been violated:
create trigger Patrol_NoOverlap_AIU on Patrol for insert, update as
begin
if exists (select *
from inserted i
inner join Patrol p
on i.GuardId = p.GuardId
and i.PatrolId <> p.PatrolId
where (i.Starts between p.starts and p.Ends)
or (i.Ends between p.Starts and p.Ends))
rollback transaction
end
NOTE: Rolling back a transaction within a trigger will terminate the batch. Unlike a normal contraint violation, you will not be able to catch the error.
You may want a different where clause depending on how you define the time range and overlap. For instance if you want to be able to say Guard #1 is at X from 6:00 to 7:00 then Y 7:00 to 8:00 the above would not allow. You would want instead:
create trigger Patrol_NoOverlap_AIU on Patrol for insert, update as
begin
if exists (select *
from inserted i
inner join Patrol p
on i.GuardId = p.GuardId
and i.PatrolId <> p.PatrolId
where (p.Starts <= i.Starts and i.Starts < p.Ends)
or (p.Starts <= i.Ends and i.Ends < p.Ends))
rollback transaction
end
Where Starts is the time the guarding starts and Ends is the infinitesimal moment after guarding ends.
The simplest way would be to use a stored procedure for the inserts. The stored procedure can do the insert in a single statement:
insert into YourTable
(GuardID, Starts, Ends)
select #GuardID, #Starts, #Ends
where not exists (
select *
from YourTable
where GuardID = #GuardID
and Starts <= #Ends
and Ends >= #Start
)
if ##rowcount <> 1
return -1 -- Failure
In my experience triggers and constraints with UDF's tend to become very complex. They have side effects that can require a lot of debugging to figure out.
Stored procedures just work, and they have the added advantage that you can deny INSERT permissions to clients, giving you fine-grained control over what enters your database.
CREATE TRIGGER [dbo].[emaill] ON [dbo].[email]
FOR INSERT
AS
BEGIN
declare #email CHAR(50);
SELECT #email=i.email from inserted i;
IF #email NOT LIKE '%_#%_.__%'
BEGIN
print 'Triggered Fired';
Print 'Invalid Emaill....';
ROLLBACK TRANSACTION
END
END
Can be done with constraints too:
http://www2.sqlblog.com/blogs/alexander_kuznetsov/archive/2009/03/08/storing-intervals-of-time-with-no-overlaps.aspx