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<DIV><FONT size=2 face=Arial>Hi</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I ahve two geometries say A and B in the same
column.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I want to make a line between geometry A and
geometry B.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>How can I write the expression so that Postgresql
recognizes that A and B are in separate rows?</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>I have tried the following which produces a null
return.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>update a --p_id.image<BR> set one =
--the_geom = <BR> (select
st_makeline(st_makepoint(st_x(st_centroid(p_id.image.the_geom)),
st_y(st_centroid(p_id.image.the_geom))),<BR>
st_centroid(p_id.image.the_geom)) <BR> from p_id.image<BR> where
(p_id.image.fluid_id = '1513'<BR> and p_id.image.description =
'A')<BR> and (p_id.image.fluid_id = '1513'<BR> and
p_id.image.description = 'B'))</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Bob</FONT></DIV></BODY></HTML>