[postgis-users] Geometry vs Linestring

[Nicolas Ribot]

Hi,

You could also cast the call to st_makeline into a specific geometry type,
with some SRID (or 0 if data has no SRID) :

... ST_MakeLine(seeds.geom)::geometry(Linestring, <srid>)

Nicolas




On 7 May 2014 15:56, Stephen Woodbridge <woodbri at swoodbridge.com> wrote:

> Linestrings are geometry objects. If you want your table to have tighter
> constraints on it create the table first and use addgeometrycolumn() to set
> the geometry type and constraints then use
>
> insert into "l_506" (oid, geom) from SELECT ...
>
> CREATE TABLE AS does not know what the query will return as far as
> geometry types so it make a general "geometry" column.
>
> -Steve
>
>
> On 5/7/2014 9:38 AM, Pier Lorenzo Marasco wrote:
>
>> Hi all,
>>
>> I'm trying to make something very easy but I've a problem with results.
>> I've two tables and I need to make lines from the joins of these two.
>> I've try with this :
>>
>> CREATE TABLE "l_506" AS
>> SELECT elements.oid, ST_MakeLine(seeds.geom) AS geom
>> FROM elements
>>     JOIN seeds ON (elements.oid=seeds.oid)
>> WHERE elements.code='0506'
>> GROUP BY elements.oid;
>>
>> All the elements in seeds are linestring but what I achieve is a
>> geometry table. Ok.. I should alter the column type and everything goes
>> as I aspect but I would like to understand where I'm getting wrong.
>>
>> L.
>>
>> --
>> Pier Lorenzo Marasco
>>
>>
>>
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>>
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