On 2014-03-14, 2:09 AM, liliwow wrote:
> Please quick help, because I'm in a fix
>
> 1 Tables: mounted device, the elements included in the devices, the link
> elements with devices (including the number of elements in the device),
> installation steps.
> 2 The counting of the number of elements needed to perform the contract
> assembly of a certain number of devices (eg, 100 units of computers in the
> configuration 1).
Generally speaking, generic assembly-of-parts queries, eg how many X do I need
to make a Y, this tends to be recursive and so you probably want to use a WITH
RECURSIVE somewhere in your query; such as that is what lets you do this query
without having to write procedural code or a query that only works for a
specific number of levels. -- Darren Duncan