SQL Server: the ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION - sql-server

Question

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

Answer 1

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. :)