On 2017-12-30 15:08, 'Udo Spallek' via tryton-dev wrote:
> Hi,
>
> I would like to extend account_invoice.Invoice.search_total_amount[A]
> which is based on a python-sql query.
> It should be extended with another module.
> In my extension I would like to replace the following column[B]::
>
> Coalesce(Sum(Round(
> (
> line.quantity * line.unit_price).cast(type_name),
> currency.digits)), 0).as_('total_amount'),
>
> with something like this::
>
> Coalesce(Sum(Round(
> (
> line.quantity * line.unit_price * (1 - line.discount /
> 100.0) ).cast(type_name), currency.digits)), 0).as_('total_amount')
>
>
>
> With introspection I found the column::
>
> columns = list(
> result[0][2].columns[0].table.select.im_self
> .queries[0].columns)
>
> But I have no idea, how to replace the column, because I have not the
> correct line object from the depends module.
> When I try something like this::
>
> pool = Pool()
> Line = pool.get('account.invoice.line')
> line = Line.__table__()
>
> columns[1] = Coalesce(Sum(Round((
> line.quantity * line.unit_price * (1 - line.discount / 100.0)
> ).cast(type_name), currency.digits)), 0).as_('total_amount')
>
> result[0][2].columns[0].table.select.im_self.queries[0].columns = \
> tuple(columns)
>
> the line table is wrong, I need the table from [B].Yes, you must take it from the 'from_' of the select but it is a complicated task and fragile. > Questions: > 1. Is it a good practice trying to extend python-sql? Not really this way. The usual way is to have composable query. > 2. Is there a better way to introspect the python-sql then this:: > > columns = list( > result[0][2].columns[0].table.select.im_self > .queries[0].columns) Normally you should not need to use 'im_self' attributes otherwise it seems OK. But as I said it is quite fragile as it will fail if any order is changed in the initial query. > 3. How to get the line-object from the base sql? It is stored in the 'from_' of the SelectQuery. In general, I think it is the wrong way to implement a discount. The discount should modify the unit price. Otherwise you are changing the definition of the field 'unit_price' and this may break other modules which may rely on it. -- Cédric Krier - B2CK SPRL Email/Jabber: cedric.kr...@b2ck.com Tel: +32 472 54 46 59 Website: http://www.b2ck.com/ -- You received this message because you are subscribed to the Google Groups "tryton-dev" group. To view this discussion on the web visit https://groups.google.com/d/msgid/tryton-dev/20180104102605.GC3925%40kei.
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