SQLTransaction and T-SQL transactions

rollbacksql-server-2005transactionstsql

I am using .NET 2.0 and SQL Server 2005. For historical reasons, the app code is using SQLTransaction but some of the stored procedures are also using T-SQL begin/commit/rollback tran statements. The idea is that the DBTransaction can span many stored procedures, which each individual sproc controls what's happening in its scope – in effect these are nested transactions.

The old behavior of the code was that if any of the sprocs failed, application logic would also cause the outer SQLTransaction to also rollback. But now we want to change the logic so that, even if there is a failure, the outer transaction should continue executing the remaining sprocs in its sequence, then at the end, since we know there were failures, we rollback the entire SQLTransaction.

The problem is that, at least as it is presently coded, is that if any of the sprocs does a ROLLBACK, the outer SQLTransaction appears to lose its connection, so any subsequent attempt at reusing the transaction fail. Is there a way I can rollback in T-SQL but still maintain the outer SQLTransaction? I was thinking that maybe savepoints might be helpful here, but I don't understand them very well yet.

What complicates this situation is that there is not always an outer transaction, so I can't just remove the T-SQL rollbacks, ie. sometimes a sproc is executed on its own; sometimes in the context of a transaction.

Would switching to TransactionScope make things easier?

Thanks for any suggestions…Mike

Best Answer

Take a look at this knowledgebase entry:

An unexpected exception may occur when a transaction is committed or rolled back after a data source error has occurred

Rolling back a transaction within a stored proc will cause any "outer" transaction in your ADO.NET client to disappear. The only solution is to wrap your Rollback() call in a try/catch block. I don't believe it's possible to maintain the outer transaction if that happens.

Syntax:

ALTER TABLE {TABLENAME} 
ADD {COLUMNNAME} {TYPE} {NULL|NOT NULL} 
CONSTRAINT {CONSTRAINT_NAME} DEFAULT {DEFAULT_VALUE}
WITH VALUES

Example:

ALTER TABLE SomeTable
        ADD SomeCol Bit NULL --Or NOT NULL.
 CONSTRAINT D_SomeTable_SomeCol --When Omitted a Default-Constraint Name is autogenerated.
    DEFAULT (0)--Optional Default-Constraint.
WITH VALUES --Add if Column is Nullable and you want the Default Value for Existing Records.

Notes:

Optional Constraint Name:
If you leave out CONSTRAINT D_SomeTable_SomeCol then SQL Server will autogenerate
a Default-Contraint with a funny Name like: DF__SomeTa__SomeC__4FB7FEF6

Optional With-Values Statement:
The WITH VALUES is only needed when your Column is Nullable
and you want the Default Value used for Existing Records.
If your Column is NOT NULL, then it will automatically use the Default Value
for all Existing Records, whether you specify WITH VALUES or not.

How Inserts work with a Default-Constraint:
If you insert a Record into SomeTable and do not Specify SomeCol's value, then it will Default to 0.
If you insert a Record and Specify SomeCol's value as NULL (and your column allows nulls),
then the Default-Constraint will not be used and NULL will be inserted as the Value.

Notes were based on everyone's great feedback below.
Special Thanks to:
@Yatrix, @WalterStabosz, @YahooSerious, and @StackMan for their Comments.

Sql – How to return only the Date from a SQL Server DateTime datatype

SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, @your_date))

for example

SELECT DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()))

gives me

2008-09-22 00:00:00.000

Pros:

No varchar<->datetime conversions required
No need to think about locale

Best Answer

Related Solutions

Sql – Add a column with a default value to an existing table in SQL Server

Syntax:

Example:

Notes:

Sql – How to return only the Date from a SQL Server DateTime datatype

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