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Re: [libreoffice-users] Base/HSQL table with more than two dimensions?


On Wed, 24 Jun 2020 02:28:45 -0400
John Kaufmann <kaufmann@nb.net> wrote:

> A lectionary is an ordered set of readings, typically using a cycle
> of three or more years, to cover the Bible. In a four-year cycle the
> years are simply designated {A,B,C,D}, and for each day in a year
> readings are prescribed from different parts of the Bible. For any
> year, storing the readings in a database table is straightforward in
> two dimensions [fields (readings) x records (days)], and it is simple
> to SELECT the set of readings (usually from four different fields)
> for any day.
>
> Obviously it is possible to do this in one table per year (say, four
> tables for four years), but since the pattern of records and fields
> is the same for all years, that is clumsy and should be unnecessary.
> It should be possible to do a table of three dimensions, of which the
> third dimension is the year {A,B,C,D} in the cycle, so that one could
> compare the readings for any given day across all years. But I don't
> see how to extend tables into three (as in this case) or more
> dimensions. Can someone point me in the right direction? [It seems
> like this kind of database design issue should be common to a lot of
> domains.]

Every extra field added to a record creates another dimension in data
space. So you just need to add a column called, say, year that can take
each of the values 'A', 'B', 'C' or 'D' and then add that field to your
SELECT statement.

> Thanks,
> John
>


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[libreoffice-users] Base/HSQL table with more than two dimensions?John Kaufmann <kaufmann@nb.net>
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