Rollback INSERT Command in C#.NET - c#-4.0

Question

I had some confusion which I want to clear it - I am inserting values into database using ADO.NET. Let say I want to insert 10 item if I encounter error while inserting data of 5th item it should roll back whatever I had inserted into the database.
I just read the concept of Transaction and Rollback method and also tried to implement it in the program but still it insert 4 item and give me error message of 5th item. It doesn't roll back insert query.
Does transaction and roll back method solved my issue or I need to used other alternative.
here is my code,
for (int i = 0; i < itemLength - 1; i++)
{
//--- Start local transaction ---
myTrans = Class1.conn.BeginTransaction();
//--- Assign transaction object and connection to command object for a pending local transaction ---
_insertQry = Class1.conn.CreateCommand();
_insertQry.Connection = Class1.conn;
_insertQry.Transaction = myTrans;
_insertQry.CommandText = "INSERT INTO Product_PropertyValue(ItemNo, PropertyNo, ValueNo) VALUES (#ItemNo, #PropertyNo, #ValueNo)";
//_insertQry = new SqlCommand("INSERT INTO Product_PropertyValue(ItemNo, PropertyNo, ValueNo) VALUES (#ItemNo, #PropertyNo, #ValueNo)", Class1.conn);
_insertQry.Parameters.AddWithValue("#ItemNo", _itemNo[i]);
_insertQry.Parameters.AddWithValue("#PropertyNo", _propNo);
_insertQry.Parameters.AddWithValue("#ValueNo", _propValue);
_insertQry.ExecuteNonQuery();
myTrans.Commit();
}
Can anyone help me?

Answer 1

It sounds like you are trying to achieve an atomic commit. It either inserts completely or doesn't insert at all.
Try something like the following
SqlTransaction objTrans = null;
using (SqlConnection objConn = new SqlConnection(strConnString))
{
objConn.Open();
objTrans = objConn.BeginTransaction();
SqlCommand objCmd1 = new SqlCommand("insert into tbExample values(1)", objConn);
SqlCommand objCmd2 = new SqlCommand("insert into tbExample values(2)", objConn);
try
{
objCmd1.ExecuteNonQuery();
objCmd2.ExecuteNonQuery();
objTrans.Commit();
}
catch (Exception)
{
objTrans.Rollback();
}
finally
{
objConn.Close();
}
Also take a look at
http://www.codeproject.com/Articles/10223/Using-Transactions-in-ADO-NET

Answer 2

I did 2 modification to your code
1) Move the BeginTransaction() outside the for loop, So that all your 10 INSERt statements are in a single transaction, that is what you want if you want them to be atomic
2) added a TRY/CATCH block, so that you can roll back in case of errors.
//--- Start local transaction ---
myTrans = Class1.conn.BeginTransaction();
bool success = true;
try
{
for (int i = 0; i < itemLength - 1; i++)
{
//--- Assign transaction object and connection to command object for a pending local transaction ---
_insertQry = Class1.conn.CreateCommand();
_insertQry.Connection = Class1.conn;
_insertQry.Transaction = myTrans;
_insertQry.CommandText = "INSERT INTO Product_PropertyValue(ItemNo, PropertyNo, ValueNo) VALUES (#ItemNo, #PropertyNo, #ValueNo)";
//_insertQry = new SqlCommand("INSERT INTO Product_PropertyValue(ItemNo, PropertyNo, ValueNo) VALUES (#ItemNo, #PropertyNo, #ValueNo)", Class1.conn);
_insertQry.Parameters.AddWithValue("#ItemNo", _itemNo[i]);
_insertQry.Parameters.AddWithValue("#PropertyNo", _propNo);
_insertQry.Parameters.AddWithValue("#ValueNo", _propValue);
_insertQry.ExecuteNonQuery();
}
}
catch (Exception ex)
{
success = false;
myTrans.Rollback();
}
if (success)
{
myTrans.Commit();
}
let me know if this doesn't works.

Answer 3

You are on the right path, ADO.NET supports transactions so you will be able to rollback on errors.
Posting your your code here would get you more specific guidance; However since your question is very generic, I will encourage you to follow the template provided by MSDN
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
// Start a local transaction.
SqlTransaction sqlTran = connection.BeginTransaction();
// Enlist a command in the current transaction.
SqlCommand command = connection.CreateCommand();
command.Transaction = sqlTran;
try
{
// Execute two separate commands.
command.CommandText =
"INSERT INTO Production.ScrapReason(Name) VALUES('Wrong size')";
command.ExecuteNonQuery();
command.CommandText =
"INSERT INTO Production.ScrapReason(Name) VALUES('Wrong color')";
command.ExecuteNonQuery();
// Commit the transaction.
sqlTran.Commit();
Console.WriteLine("Both records were written to database.");
}
catch (Exception ex)
{
// Handle the exception if the transaction fails to commit.
Console.WriteLine(ex.Message);
try
{
// Attempt to roll back the transaction.
sqlTran.Rollback();
}
catch (Exception exRollback)
{
// Throws an InvalidOperationException if the connection
// is closed or the transaction has already been rolled
// back on the server.
Console.WriteLine(exRollback.Message);
}
}
}