I don't know how to use if else in this case. When score > 10, stop insert. Else continue insert as normally. But what is the syntax to do that?
CREATE TRIGGER invalidScore ON dbo.dbo_score
AFTER INSERT
AS
DECLARE #score DECIMAL;
SET #score = (SELECT s.score FROM Inserted s);
IF(#score > 10)
BEGIN
RETURN 'score must be less than 10'
ROLLBACK TRAN
END
ELSE
BEGIN
END
There are 3 things you need to change for this trigger to work:
Remove the else section - its optional.
Handle the fact that Inserted may have multiple rows.
Throw the error rather than using the return statement so you can handle it in the client. And throw it after rolling back the transaction in progress.
Corrected trigger follows:
create trigger invalidScore on dbo.dbo_score
after insert
as
begin
if exists (select 1 from Inserted S where S.Score > 10) begin
rollback tran;
throw 51000, 'score must be less than 10', 1;
end
end
First, creating these types of sql objects should use begin.. end blocks. Second is,you can ignore the else statement.
CREATE TRIGGER invalidScore ON dbo.dbo_score
AFTER INSERT
AS
BEGIN
DECLARE #score DECIMAL;
SET #score = (SELECT s.score FROM Inserted s);
IF(#score > 10)
BEGIN
RETURN 'score must be less than 10'
ROLLBACK TRAN
END
END
'Else' is an option section you can remove this and use it,but i may like you to consider using check constraints for scenarios like this rather than adding a trigger check on score column
e.g.
CREATE TABLE dbo.dbo_score(
Score int CHECK (score < 10)
);
A CHECK constraint is faster, simpler, more portable, needs less code and is less error prone
Related
I have a trigger that works (it fires when it has to) but I still get an error.
I understand the error but I don't know how to resolve it.
I tried to put some BEGIN TRANSACTION with all the code who go with it but I think my grammar is wrong because I always get a timeout!
So my question is, where exactly do I have to put my BEGIN TRANSACTION statements in my code?
Also, do I need 3 BEGIN TRANSACTION statements since I have 3 ROLLBACK?
Thank you in advance!
My code:
ALTER TRIGGER [dbo].[Tr_CheckOverlap]
ON [dbo].[Tranche]
FOR INSERT
AS
BEGIN
SET NOCOUNT ON;
DECLARE #IdVol INT, #IdTranche INT,
#AgeMinInserted DATE, #AgeMaxInserted DATE
SELECT #AgeMinInserted = t.TRA_Age_Min
FROM Tranche t
JOIN inserted AS i ON t.TRA_Id = i.TRA_Id
SELECT #AgeMaxInserted = t.TRA_Age_Max
FROM Tranche t
JOIN inserted AS i ON t.TRA_Id = i.TRA_Id
DECLARE CR_TrancheVol CURSOR FOR
SELECT t.TRA_Vol_Id,t.TRA_Id
FROM Tranche t
JOIN inserted AS i ON t.TRA_Vol_Id = i.TRA_Vol_Id;
OPEN CR_TrancheVol
FETCH CR_TrancheVol INTO #IdVol, #IdTranche
WHILE( ##FETCH_STATUS = 0)
BEGIN
DECLARE #AgeMin DATE, #AgeMax DATE
SELECT #AgeMin = t.TRA_Age_Min
FROM Tranche t
WHERE t.TRA_Id = #IdTranche
SELECT #AgeMax = t.TRA_Age_Max
FROM Tranche t
WHERE t.TRA_Id = #IdTranche
IF #AgeMinInserted > #AgeMin AND #AgeMinInserted < #AgeMax
BEGIN
PRINT 'Trans1'
RAISERROR('Overlap: Date de naissance minimum déjà couverte', 1, 420)
ROLLBACK TRANSACTION
END
IF #AgeMaxInserted > #AgeMin AND #AgeMaxInserted < #AgeMax
BEGIN
PRINT 'Trans2'
RAISERROR('Overlap: Date de naissance maximum déjà couverte', 1, 421)
ROLLBACK TRANSACTION
END
IF #AgeMinInserted < #AgeMin AND #AgeMaxInserted > #AgeMax
BEGIN
PRINT 'Trans3'
RAISERROR('Overlap: Tranche déjà couverte complètement', 1, 422)
ROLLBACK TRANSACTION
END
FETCH CR_TrancheVol INTO #IdVol, #IdTranche
END
CLOSE CR_TrancheVol
DEALLOCATE CR_TrancheVol
END
EDIT:
Okay, so I tried your answer without cursor (I understand that my way was clearly not the best!) but for now it doesn't work.
My goal: I have a DB to book a flight. In this DB, i have a table "Tranche" who contains some dates and some prices (depending when the flight is).
I need to prevent and avoid any overlap of birthdate, for example:
1y-17y: 80€
18y-64y: 120€
So my trigger has to fire when I try to insert 17y-63y: xx € (because I already have a price for those ages).
Sorry if my English is not perfect btw!
Here's my table "Tranche":
https://i.stack.imgur.com/KuQH8.png
TRA_Vol_ID is a foreign key of another table "Vol" who contain the flights
Here's the code I have atm:
ALTER TRIGGER [dbo].[Tr_CheckOverlap]
ON [dbo].[Tranche]
FOR INSERT
AS
BEGIN
/*
Some SQL goes here to get the value of Minimum age.
I assuming that it doesn't vary by entry, however,
I don't really have enough information to go on to tell
*/
SET NOCOUNT ON;
DECLARE #MinAge DATE, #MaxAge DATE
SELECT #MinAge = t.TRA_Age_Min
FROM Tranche t
JOIN Vol AS v ON v.VOL_Id = t.TRA_Vol_Id
JOIN inserted AS i ON t.TRA_Id = i.TRA_Id
WHERE t.TRA_Id = i.TRA_Id
SELECT #MaxAge = t.TRA_Age_Max
FROM Tranche t
JOIN inserted AS i ON t.TRA_Id = i.TRA_Id
JOIN Vol AS v ON v.VOL_Id = t.TRA_Vol_Id
WHERE t.TRA_Id = i.TRA_Id
IF (SELECT COUNT(CASE WHEN i.TRA_Age_Min > #MinAge AND i.TRA_Age_Min < #MaxAge THEN 1 END) FROM inserted i) > 0
BEGIN
RAISERROR('Overlap: Birthday min reached',1,430);
ROLLBACK
END
ELSE IF (SELECT COUNT(CASE WHEN i.TRA_Age_Max > #MinAge AND i.TRA_Age_Max < #MaxAge THEN 1 END) FROM inserted i) > 0
BEGIN
RAISERROR('Overlap: Birthday max reached',1,430);
ROLLBACK
END
END
I don't really know what the OP's goals are here. However, I wanted to post a small example how to do a dataset approach, and how to check all the rows in one go.
At the moment, the trigger the OP has will only "work" if the user is inserting 1 row. Any more, and things aren't going to work properly. Then we also have the problem of the CURSOR. I note that the declaration of the cursors aren't referencing inserted at all, so I don't actually know what their goals are. It seems more like the OP is auditing the data already in the table when a INSERT occurs, not the data that is being inserted. This seems very odd.
Anyway, this isn't a solution for the OP, however, I don't have enough room in a comment to put all this. Maybe it'll push the OP in the right direction.
ALTER TRIGGER [dbo].[Tr_CheckOverlap]
ON [dbo].[Tranche]
FOR INSERT
AS
BEGIN
/*
Some SQL goes here to get the value of Minimum age.
I assuming that it doesn't vary by entry, however,
I don't really have enough information to go on to tell
*/
IF (SELECT COUNT(CASE WHEN i.Age < #MinAge THEN 1 END) FROM inserted i) > 0 BEGIN
RAISERROR('Age too low',1,430);
ROLLBACK
END
ELSE
IF (SELECT COUNT(CASE WHEN i.Age > #MaxAge THEN 1 END) FROM inserted i) > 0 BEGIN
RAISERROR('Age too high',1,430);
ROLLBACK
END
END
The question at hand seems to very much be an xy question; the problem isn't the CURSOR or the ROLLBACK, the problems with this trigger are much more fundamental. I'd suggest revising your question and actually explaining your goal of what you want to do with your Trigger. Provide DDL to CREATE your table and INSERT statements for any sample data. You might want to also provide some INSERT statements that will have different results for your trigger (make sure to include ones that have more than one row to be inserted at a time).
I realise this is more commenting, however, again, there is definitely not enough room in a comment for me to write all this. :)
I am trying to write a stored procedure that reads a column in a particular row of a table, then updates that column with a new value. The orig. is returned.
I want it to lock the row from others till I am done. What is the process?
I have something like
CREATE PROCEDURE [dbo].[aptc_Prt_NextDocumentNumberGet]
(#_iFormatConfigID INT, #_oNextDocumentNumber FLOAT OUTPUT)
AS
BEGIN
DECLARE #FrameworkConfig XML
SET #_oNextDocumentNumber = - 1
DECLARE #NewNextDocumentID FLOAT
SELECT
#_oNextDocumentNumber = FrameworkConfig.value('(/Parameters/Parameter[#Name="NextDocNo.NextDocumentNumber"])[1]', 'float')
FROM
[ttcPrtFormatConfig] WITH (ROWLOCK)
WHERE
FormatConfigID = #_iFormatConfigID
-- Select the Next Doc num out of the xml field
-- increment appropriate control and set output
IF #_iFormatConfigID IS NOT NULL
BEGIN
-- set what will be the "next" doc number after we add this current txn
IF (ABS(#_oNextDocumentNumber - 99999999999999999) < 0.0001)
BEGIN
SELECT #NewNextDocumentID = 1
END
ELSE
BEGIN
SELECT #NewNextDocumentID = #_oNextDocumentNumber + 1
END
UPDATE [ttcPrtFormatConfig]
WITH (ROWLOCK)
SET FrameworkConfig.modify('
replace value of
(/Parameters/Parameter[#Name="NextDocNo.NextDocumentNumber"]/text())[1]
with sql:variable("#NewNextDocumentID")')
WHERE FormatConfigID = #_iFormatConfigID
END
END
This should get you close to what you want.
DECLARE #MyValue INT
--You need a transaction so that the scope of your lock is well defined
BEGIN TRANSACTION
BEGIN TRY
--Get the value you are interested in, This select will lock the row so other people will not even be able to read it until you are finished!!!!!
SELECT #MyValue = MyValue
FROM MyTable WITH (UPDLOCK HOLDLOCK)
WHERE MyValue = SomeValue
--Do your checks and updates. You can take as long as you like as you are the only person who can do a read or update of this data.
IF
BEGIN
UPDATE MyTable
END
--Make sure you commit or rollback! this will release the lock
END TRY
BEGIN CATCH
--Oh no bad stuff! give up and put it back to how it was
PRINT ERROR_MESSAGE() + N' Your message here'
--Check there is a transaction that we can rollback
IF ##TRANCOUNT > 0
BEGIN
ROLLBACK;
END
--You may want to return some error state and not throw!
THROW;
--RETURN -1 --(for example)
END CATCH;
--yay it all worked and your lock will be released
COMMIT
--Do what you like with the old value
RETURN #MyValue
I am working with Sage Evolution and do a lot of the back end stuff to customize it for our company.
I need to write a query where, when a user enters a negative quantity the system must not allow the transaction, however when the user enters a negative quantity and the product belongs to the "chemicals" group it needs to process the transaction.
Here is my code I have written so far.
DECLARE
#iAfterfQuantity Int;
#iAfteriStockCodeID Int;
#iAfterStockItemGroup VarChar
SELECT
#iAfterfQuantity = fQuantity,
#iAfteriStockCodeID = iStockCodeID
FROM
INSERTED
SELECT
#iAfterStockItemGroup = ItemGroup
FROM
dbo.stkItem
WHERE
StockLink = #iAfteriStockCodeID
BEGIN
IF #iAfterfQuantity < 0 AND #iAfterStockItemGroup <> 'chemicals'
BEGIN
RAISERROR ('',16,1)
ROLLBACK TRANSACTION
END
END
This is a task better suited for a check constraint then for a trigger, especially considering the fact that you are raising an error.
First, create the check function:
CREATE FUNCTION fn_FunctionName
(
#iAfterfQuantity Int,
#iAfteriStockCodeID Int
)
RETURNS bit
AS
BEGIN
DECLARE #iAfterStockItemGroup VarChar(150) -- Must specify length!
SELECT #iAfterStockItemGroup = ItemGroup FROM dbo.stkItem WHERE StockLink=#iAfteriStockCodeID
IF #iAfterfQuantity < 0 AND #iAfterStockItemGroup <> 'chemicals'
RETURN 0
RETURN 1 -- will be executed only if the condition is false...
END
Then, alter your table to add the check constraint:
ALTER TABLE YourTableName
ADD CONSTRAINT ck_ConstraintName
CHECK (dbo.fn_FunctionName(fQuantity, iStockCodeID) = 1)
GO
I need to make a trigger that checks if an airplane seat is taken before a customer can be inserted into the table.
I have the following Trigger so far:
CREATE TRIGGER CheckIfSeatIsUnique
ON PassagierVoorVlucht
AFTER insert, update
AS
BEGIN
IF ##ROWCOUNT = 0 RETURN
SET NOCOUNT ON
BEGIN TRY
IF EXISTS (SELECT 1 FROM PassagierVoorVlucht P Join inserted I on P.vluchtnummer=i.vluchtnummer Where P.stoel = I.stoel)
BEGIN
RAISERROR('The chosen seat is taken', 16, 1)
END
END TRY
BEGIN CATCH
IF ##TRANCOUNT > 0
ROLLBACK TRANSACTION
DECLARE #ErrorMessage NVARCHAR(4000) = ERROR_MESSAGE()
DECLARE #ErrorSeverity INT = ERROR_SEVERITY()
DECLARE #ErrorState INT = ERROR_STATE()
RAISERROR (#ErrorMessage, #ErrorSeverity, #ErrorState)
END CATCH
END
The problem I have, is that the trigger checks if the seat is taken AFTER the insert was done, So the seat will always be taken no matter what.
Is there some way to check if the seat is taken before the insert is done?
Edit: It must also be possible to enter NULL on seat, because the seatnumber isn't known till a few days before the flight
If you have a unique identifier on the table, you can join it into the EXISTS() query to filter out any records that were attempted to insert.
The fiddle below examples this, though it assumes you're taking care of an null handling you need to outside of this.
http://sqlfiddle.com/#!6/93a8a
CREATE TRIGGER CheckIfUnique_mydata_value ON dbo.data
AFTER insert, update
AS
BEGIN
--check if we passed multiple values
IF EXISTS(SELECT 1 FROM inserted GROUP BY value HAVING COUNT(*) > 1)
BEGIN
RAISERROR('You tried to insert a duplicate value within the result set. Ensure you only pass unique values!', 16,1)
END
--check if we inserted a value that already exists that is not me (works for updates on me too!)
IF EXISTS(SELECT 1 FROM dbo.data m INNER JOIN inserted i ON m.value = i.value AND m.id <> i.id)
BEGIN
RAISERROR('Duplicate Value found',16,1)
END
END;
I'm using the following code in sql server 2005.
BEGIN TRANSACTION;
CREATE TABLE dbo.MyTable
(
idLang int NOT NULL IDENTITY (1, 1),
codeLang nvarchar(4) NOT NULL
) ON [PRIMARY];
IF ##ERROR = 0
BEGIN
PRINT 'before_commit';
COMMIT TRANSACTION;
PRINT 'after_commit';
END
ELSE
BEGIN
PRINT 'before_rollback';
ROLLBACK TRANSACTION;
PRINT 'after_rollback';
END
GO
1 - Display when MyTable doesn't exist (no error case) :
before_commit
after_commit
=> OK
2 - Display when MyTable exists (error case) :
'There is already an object named 'MyTable' in the database.'
=> Why the "else" statement is not executed ? (no print, no rollback)
I know the alternative with try-catch but i'd like to understand this strange case...
Thanks !
The CREATE TABLE will be checked during query compilation and fail, so none of the code in the batch is executed. Try adding:
SELECT ##TRANCOUNT
To the end of the script (i.e. after the GO), and you'll see the BEGIN TRANSACTION never occurred either.
I can't say specifically why your problem is occurring. Personally, I'm not sure I would use a transaction and error handling or a try/catch block to do this.
Have you tried querying the sys.tables table instead to check for its existence. Something of this ilk:
IF EXISTS(SELECT * FROM sys.tables WHERE object_id = object_id('MyTable'))
BEGIN
print 'table already exists'
END
ELSE
BEGIN
CREATE TABLE dbo.MyTable
(
idLang int NOT NULL IDENTITY (1, 1),
codeLang nvarchar(4) NOT NULL
) ON [PRIMARY];
END