Re: Table filter
От | Joe Conway |
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Тема | Re: Table filter |
Дата | |
Msg-id | 47448586.6050107@joeconway.com обсуждение исходный текст |
Ответ на | Table filter (Reg Me Please <regmeplease@gmail.com>) |
Ответы |
Re: Table filter
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Список | pgsql-general |
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
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