Question

Is using Commit in a transaction enough or I should use rollback too.

tabel1
  name   nvarchar(10)
  family nvarchar(20)

table 2 
    name nvarchar(10)
    family nvarchar(20) not null

begin transaction
insert into table2 (name) values('john')
insert into table1 (name,family) values('Joe','Lando')
commit transaction

as you see the first statement has error. should I use rollback somewhere?

Answer 1

You can skip ROLLBACK if you use SET XACT_ABORT ON (SQL Server 2000 link)

SET XACT_ABORT ON
begin transaction
insert into table2 (name) values('john')
insert into table1 (name,family) values('Joe','Lando')
commit transaction

From the link:

When SET XACT_ABORT is ON, if a Transact-SQL statement raises a run-time error, the entire transaction is terminated and rolled back.

Now, if you don’t use it you need rollback. Or close your connection.

One useful side effect of SET XACT_ABORT ON is that after a client CommandTimeout event, locks are released and the transactions rolled back. Otherwise, it doesn’t happen until the connection is hard removed from SQL Server: it can stay open because of pooling.

Your bible should be “Error Handling in SQL 2000 – a Background” by Erland Sommarskog: read it. And on SO: Do I really need to use "SET XACT_ABORT ON"?