Reg Me Please wrote:
The meaning is that an entity called by the value of "item" has a number
of properties called by "property" with value "prop_value".
So, for a single "item" there can be many different "property" each with its
own value.
A filter is a list of property values needed to qualify an entity as
"good". An entity evaluates as good only when all property values in the
filter match the ones associated to an item in t_data.
What's missing to me is how to apply a filter to the t_data and get the list
of the items that evaluate good.
I haven't played with it myself, but it seems to me that you could do
this with an inner join of two crosstabs -- one on t_data and one on the
filters (i.e. you join on the columns of the filter crosstab to the
matching ones in the t_data crosstab).
Joe
---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faq
