[fpc-devel] Implementing a Dataset

[michael.vancanneyt at wisa.be]

On Mon, 3 Sep 2012, Felipe Monteiro de Carvalho wrote:

> On Mon, Sep 3, 2012 at 11:18 AM,  <michael.vancanneyt at wisa.be> wrote:
>> I think your best bet is to create a descendent of TBufDataset: it is in
>> itself a full TDataset.
>>
>> You'll have to implement the least amount of methods there, and you can see
>> in TSQLQuery which ones.
>
> But why would this be a better solution? TBufDataset is huge ... it me
> it looks much harder to understand how it works and subclass it then
> to attempt to start with empty methods and see if implementing
> something on them will work.

Believe me, it is not :-)

And do not forget, you don't need to do TBufDataset, but TSQLQuery.
That just implements a few simple things. The rest is taken care of by
TBufDataset.

In essence you need to define which fields you need (i.e. populate
TFieldDefs) and then a routine to copy data from the source to the buffer,
and vice versa.

If you want, you can also look at the JSON Dataset. That is quite simple.

Michael.