Re: [GNUe-dev] New condition-element available to Appserver

[malek]

hi,

what would be the correct syntax for a session.find()?

is it:

['exist', 'class', 'master', 'detail', [subcondition...]]

or:

['exist', ['table', 'class'], ['masterlink', 'master'], ['detaillink',
'detail'], [subcondition...]]

thanks,

malek


Quoting Johannes Vetter <address@hidden>:

> Hi,
> 
> We've introduced a new condition-element 'exist'. It's main purpose is
> to perform a sub-select and to return False if that sub-select was empty
> or True if it was not empty.
> 
> Example: Invoicing
> 
> I want to see all customers that have an order for item 'FOO'.
> 
> 
> Here comes the XML-Syntax of the new condition-element:
> 
> <datasource name="dtsFoo" ...>
>  <condition>
>  ...
>  <exist table="detailtable" masterlink="f,f,..." detaillink="f,f,...">
>   <condition>...</condition>
>  </exist>
>  ...
>  </condition>
> </datasource>
> 
> 'table' defines the table to be queried by the sub-select.
> 'masterlink' specifies the fields to be compared from the current
> datasource (i.e. 'dtsFoo')
> 'detaillink' specifies the fields in 'table', which must match with the
> fields in 'masterlink'. Note: the order and number of items must be the
> same.
> 
> An optional 'sub-condition' could be added. If it is given, this
> condition will be used as condition for the subselect.
> 
> 
> Example:
> 
> (To see the structures used for this example, please have a look at
> gnue-appserver/samples/testing/joins/struct.gcd)
> 
> 
> <datasource name="dtsCust" connection="appserver" table="test_customer">
>     <condition>
>       <exist table="test_lineitem" masterlink="gnue_id"
>              detaillink="test_invoice.test_customer">
>         <eq>
>           <cfield name="test_item.test_code" />
>           <cconst value="G1" />
>         </eq>
>       </exist>
>     </condition>
>   </datasource>
> 
> 
> The above definition would select all rows from 'test_customer', which
> have a result in: all rows from test_lineitem, where
> test_invoice.test_customer matches the former row in 'test_customer'
> *and* where 'test_item.test_code' is equal to 'G1'.
> 
> 
> 
> Thanks,
> 
> Johannes
> 
> 
> 
> -- 
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> i.A. Johannes Vetter            Fax +43 (5577) 89877-66
> A-6890 Lustenau, Enga 2         http://www.bytewise.at
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