[postgis-users] ST_UNION(linestring, linestring) returns a multilinestring

[Stephen Woodbridge]

Dane,

Thanks, that worked great.

-Steve

Dane Springmeyer wrote:
> Stephen,
> 
> Try:
> 
> select astext(st_linemerge(ST_Collect(b.the_geom)))
>  from (
>    select ST_GeomFromText('LINESTRING(35.5269251710001 
> 33.891749555,35.527091166 33.8917984710001)') as the_geom
>   union
>   select ST_GeomFromText('LINESTRING(35.527091166 
> 33.8917984710001,35.5274352000001 33.8918998510001,35.528236559 
> 33.8919810230001)') as the_geom
>  ) as b;
> 
> Thanks works for me.
> 
> Dane
> 
> 
> On Oct 7, 2008, at 2:38 PM, Stephen Woodbridge wrote:
> 
>> This does not seem to work. Am I using it wrong?
>>
>>
>> select astext(st_linemerge(b.the_geom))
>>  from (
>>    select ST_GeomFromText('LINESTRING(35.5269251710001 
>> 33.891749555,35.527091166 33.8917984710001)') as the_geom
>>   union
>>   select ST_GeomFromText('LINESTRING(35.527091166 
>> 33.8917984710001,35.5274352000001 33.8918998510001,35.528236559 
>> 33.8919810230001)') as the_geom
>>  ) as b;
>>                                                  astext
>> ----------------------------------------------------------------------------------------------------------- 
>>
>> LINESTRING(35.5269251710001 33.891749555,35.527091166 33.8917984710001)
>> LINESTRING(35.527091166 33.8917984710001,35.5274352000001 
>> 33.8918998510001,35.528236559 33.8919810230001)
>> (2 rows)
>>
>> The results that I am expecting to get are:
>>
>> LINESTRING(35.5269251710001 33.891749555,35.527091166 
>> 33.8917984710001,35.5274352000001 33.8918998510001,35.528236559 
>> 33.8919810230001)
>>
>> -Steve
>>
>>
>> Fred Lehodey wrote:
>>> =>   ST_LineMerge()
>>> Fred.
>>> On Tue, Oct 7, 2008 at 8:58 PM, David William Bitner 
>>> <bitner at gyttja.org <mailto:bitner at gyttja.org>> wrote:
>>>    Check out ST_Merge()
>>>    On Tue, Oct 7, 2008 at 3:54 PM, Stephen Woodbridge
>>>    <woodbri at swoodbridge.com <mailto:woodbri at swoodbridge.com>> wrote:
>>>        Hi all,
>>>        This is very annoying. I have two linestrings the join
>>>        end-to-end and I want to build a new single linestring by
>>>        merging the two. How can I do this?
>>>        Thanks,
>>>         -Steve
>>>        select astext( ST_Union(               
>>> ST_GeomFromText('LINESTRING(35.5269251710001
>>>        33.891749555,35.527091166 33.8917984710001)'),
>>>        ST_GeomFromText('LINESTRING(35.527091166
>>>        33.8917984710001,35.5274352000001 33.8918998510001,35.528236559
>>>        33.8919810230001)')                                    ));
>>>                     astext
>>>        
>>> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 
>>>
>>>         MULTILINESTRING((35.5269251710001 33.891749555,35.527091166
>>>        33.8917984710001),(35.527091166
>>>        33.8917984710001,35.5274352000001 33.8918998510001,35.528236559
>>>        33.8919810230001))
>>>        (1 row)
>>>        _______________________________________________
>>>        postgis-users mailing list
>>>        postgis-users at postgis.refractions.net
>>>        <mailto:postgis-users at postgis.refractions.net>
>>>        http://postgis.refractions.net/mailman/listinfo/postgis-users
>>>    --     ************************************
>>>    David William Bitner
>>>    _______________________________________________
>>>    postgis-users mailing list
>>>    postgis-users at postgis.refractions.net
>>>    <mailto:postgis-users at postgis.refractions.net>
>>>    http://postgis.refractions.net/mailman/listinfo/postgis-users
>>> ------------------------------------------------------------------------
>>> _______________________________________________
>>> postgis-users mailing list
>>> postgis-users at postgis.refractions.net
>>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
> 
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users