Re: Add: Special sort querstion
| От | Dirk Jagdmann |
|---|---|
| Тема | Re: Add: Special sort querstion |
| Дата | |
| Msg-id | 5d0f60990904010757t1d1dcbbbx1293e95e4850b31e@mail.gmail.com обсуждение исходный текст |
| Ответ на | Add: Special sort querstion (Dominik Piekarski <d.piekarski@vivawasser.de>) |
| Список | pgsql-sql |
I think it can not be done with default PostgreSQL functions and operators, because you must compare two different columns of two rows depending which row is on either side of the "<" comparision. But I think you can do this with the following steps: 1) create a new type as a 4-tupel of start_lat, end_lat, start_lng, end_lng. 2) write a comparison function for this type 3) write a SQL-Function to convert 4 values into your new type (for example: ToMyType(start_lat, end_lat, start_lnd, end_lng) returns MyType...) 4) use ToMyType in the order clause of your select If this would work, I'm interested in a working example code :-) -- ---> Dirk Jagdmann ----> http://cubic.org/~doj -----> http://llg.cubic.org
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