[postgis-users] st_collect, st_union

[Bob Pawley]

Hi

I have a table with five rows each holding a linestring geometry.

Each of theses geometries indicate true on an st_isvalid query.

All rows are displayed as expected in QGis.

However, when I run an st_union or st_collect query on all five rows the return is empty.

If I select only four of the five rows (any four)  it returns a value.

Can anyone suggest what type of problem I should look for? Is there some restriction on these functions?

Bob

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20110629/7b11be9e/attachment.html>