[Gambas-user] Use of db.Begin, db.Commit and db.Rollback with a datasource and datacontrols

[Lewis Balentine]

Nope, you did not mislead me ....

I was already been looking at these methods, but I had only tried the 
update function on a dataview control where the data was modified by an 
external program (that works nicely).

I believe that I have tried every combination of: DataSource.Cancel, 
DataSource1.Update, DataSource1.Refresh

BINGO!!
Put "DataSource.Connection.begin" just after the DB/Table is opened.
Put "DataSource.Connection.commit" and "DataSource.Connection.begin" at 
the end of each save.
Use  "DataSource.Connection.Rollback", "DataSource.Update", 
"DataSource.Connection.Begin" to cancel.

Alas I have run out of time and must attend to other matters.
I will try update my example tomorrow and upload it.
(I also want a bit more testing).

Regards,

Lewis

On 01/20/2015 01:07 PM, T Lee Davidson wrote:
> I believe I have mislead you too, Lewis. My apologies.
>
> Look at DataSource.Update.
>
>
> Lee
> __________
>
> "Artificial Intelligence is no match for natural stupidity."
>
> On 01/20/2015 01:03 PM, Lewis Balentine wrote:
>> Mr. Speaker,
>> I request permission to revise and extend my previous remarks ...
>>
>> Please see the attached sample application and data base. I used a SQlite Database but in theory these function should operate the same. I tried
>> five ways to cancel the edits to a set of data controls.
>>       via Control Refresh
>>       via Data Source Refresh
>>       via Data Source Cancel
>>       via Closing the DB and reopening it
>>       via Data Control Tags
>>
>> The only one that I found that worked was to restore the content from a copy saved in the data control tags. I note that changing the
>> 'DataControl.Value' (either via software or manually) does not set 'DataSource.Modified' or "DataControl.Modified' properties to true. The
>> operation was the same in version 3.6.2 and 3.6.9.
>>
>> Then again maybe I am doing something(s) wrong .... :-\
>>
>> Regards,
>>
>> Lewis Balentine
>>
>> On 01/19/2015 07:42 PM, T Lee Davidson wrote:
>>> Hello Martin,
>>>
>>> If you are working with only one record at a time, you don't need to use transactions.
>>> Transactions are used when multiple records need to be modified in an all-or-none scenario, such as when a record, that is the "one" in a
>>> one-to-many relationship, needs to be deleted.
>>>
>>> In such a case, you would start a transaction with .Begin, delete the dependent records followed by the one record. Then, if all modifications
>>> are successful, you would .Commit. If there is a failure at any time during the transaction, you would .Rollback.
>>>
>>> To get the datacontrol to display the original data after a canceled edit, use the .Refresh method.
>>>
>>>
>>> Lee
>>> __________
>>>
>>
>>
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> ------------------------------------------------------------------------------
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> GigeNET is offering a free month of service with a new server in Ashburn.
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> Higher redundancy.Lower latency.Increased capacity.Completely compliant.
> http://p.sf.net/sfu/gigenet
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