Re: [SQL] Add: Special sort querstion
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 -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
Re: [SQL] Add: Special sort querstion
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 -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
Re: [SQL] Add: Special sort querstion
On Fri, Mar 27, 2009 at 6:10 AM, Dominik Piekarski d.piekar...@vivawasser.de wrote: Oh, actually every row of the same id-range has the same start_lat/start_lng coordinates as the predecessors end_lat/end_lng coordinates. But the question remains the same. Is there a way to do something like ORDER BY (start_lat = end_lat AND start_lng = end_lng) ? Or maybe another way to achieve the same result? Would something like order by start_lat-endlat, start_lng-end_lng OR case when start_lat=end_lat AND start_lng=end_lng then 0 else 1 end ??? -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
