Handling Transaction from client side

Data Abstract
1

I have a datatable that I update on client side, and after calling it I need to call a method on the server that do an insert to another table, but both using the same connection.

I need to know how can I start transaction from client side, to do Applyupdates to the DataTable then call the insert method of server in one transaction.

2

Hello,

To handle transaction from the client side you need to define service methods from where you should call
Connection.BeginTransaction;
Connection.CommitTransaction;
Connection.RollBackTransaction;

in such a way:

procedure TDataService.StartTransaction;
begin
if Connection.InTransaction then
begin
Connection.RollbackTransaction;
Connection.BeginTransaction;
end
else
Connection.BeginTransaction;
end;

procedure TDataService.CommitTransaction;
begin
if Connection.InTransaction then
Connection.CommitTransaction;
end;

procedure TDataService.RollbackTransaction;
begin
if Connection.InTransaction then
Connection.RollbackTransaction;
end;

It is also necessary to set
aUseDefaultTransactionLogic:=false;

in onUpdateDataBeginTransaction and onUpdateDataBeginTransaction events of DataService.

So on the client side you will have something like this:

[…]
service.StartTransaction;

// do necessary changes in DataTable

try
ClientDataModule.tbl_Datatable.ApplyUpdates();
service.InsertIntoAnotherTable;
service.CommitTransaction;
except
service.RollbackTransaction;
end;
[…]

For this code to work correctly you should get aware that you call the same Connection instance. The most easy way for this is to off Connection Pooling (http://wiki.remobjects.com/wiki/Connection_Pooling_(Data_Abstract)) :
ConnectionManager.PoolingEnabled:=false;

Hope this helps