How Do SQL Transactions Work?

Question

I have not been working in SQL too long, but I thought I understood that by wrapping SQL statements inside a transaction, all the statements completed, or none of them did. Here is my problem. I have an order object that has a lineitem collection. The line items are related on order.OrderId. I have verified that all the Ids are set and are correct but when I try to save (insert) the order I am getting The INSERT statement conflicted with the FOREIGN KEY constraint "FK_OrderItemDetail_Order". The conflict occurred in database "MyData", table "dbo.Order", column 'OrderId'.

psuedo code:

create a transaction
transaction.Begin()
Insert order
Insert order.LineItems <-- error occurs here
transaction.Commit

actual code:

...
entity.Validate();
if (entity.IsValid)
{
    SetChangedProperties(entity);
    entity.Install.NagsInstallHours = entity.TotalNagsHours;
    foreach (OrderItemDetail orderItemDetail in entity.OrderItemDetailCollection)
    {
        SetChangedOrderItemDetailProperties(orderItemDetail);
    }
    ValidateRequiredProperties(entity);
    TransactionManager transactionManager = DataRepository.Provider.CreateTransaction();
    EntityState originalEntityState = entity.EntityState;
    try
    {
        entity.OrderVehicle.OrderId = entity.OrderId;
        entity.Install.OrderId = entity.OrderId;
        transactionManager.BeginTransaction();

        SaveInsuranceInformation(transactionManager, entity);
        DataRepository.OrderProvider.Save(transactionManager, entity);
        DataRepository.OrderItemDetailProvider.Save(transactionManager, entity.OrderItemDetailCollection);             if (!entity.OrderVehicle.IsEmpty)
        {
            DataRepository.OrderVehicleProvider.Save(transactionManager, entity.OrderVehicle);
        }
        transactionManager.Commit();
    }
    catch
    {
        if (transactionManager.IsOpen)
        {
            transactionManager.Rollback();
        }
        entity.EntityState = originalEntityState;
    }
}
...

Someone suggested I need to use two transactions, one for the order, and one for the line items, but I am reasonably sure that is wrong. But I've been fighting this for over a day now and I need to resolve it so I can move on even if that means using a bad work around. Am I maybe just doing something stupid?

Answer 1

I noticed that you said you were using NetTiers for your code generation.

I've used NetTiers myself and have found that if you delete your foreign key constraint from your table, add it back to the same table and then run the build scripts for NetTiers again after making your changes in the database might help reset the data access layer. I've tried this on occasion with positive results.

Good luck with your issue.