I have a table in a PostGIS database where with this query :
SELECT ST_CENTROID(pol8.geom) AS geom
FROM polygon8 AS pol8;
I got this:
geom
----------------------------------------------------
0101000020647F00001AFAEAE428C91641E38374F8A8015141
0101000020647F0000CB093A0DFA6C19416AFE29C6F8FB5041
0101000020647F00002D325E7A35301C411F69C65A03F95041
0101000020647F00007F7DBD9F049F1A419FDBBA0177E65041
0101000020647F00005F7B5395D9CC18416E2BB23D61E35041
0101000020647F000057844F356A0016417EA357E1A5EE5041
0101000020647F0000CAFFD8471C1A18414B9D4A488DF95041
0101000020647F000033426EF4B7B91C41C5D5530680E55041
(8 rows)
However, with this one I have a syntax error:
SELECT ST_AsText (ST_CENTROID(pol8.geom) AS geom
FROM polygon8 AS pol8);
ERROR: syntax error at or near "AS"
LINE 1: SELECT ST_AsText (ST_CENTROID(pol8.geom) AS geom
^
I only get the expected result with these additional queries (three in total):
CREATE TABLE centroids_pol8 AS (SELECT ST_CENTROID(pol8.geom) AS geom
FROM polygon8 AS pol8);
SELECT ST_AsText (geom) AS wkt
FROM centroids_pol8;
wkt
------------------------------------------
POINT(373322.223552616 4458147.88211152)
POINT(416574.512916711 4452323.0963131)
POINT(461837.369499954 4449293.41836002)
POINT(436161.155996285 4430300.0270299)
POINT(406326.395826271 4427140.96399961)
POINT(360474.552061146 4438679.52097404)
POINT(394887.070163724 4449845.1295541)
POINT(470637.988701853 4429312.09886688)
(8 rows)
I tried out many syntax forms and I can not find out the solution for a query in only one path. Where is the issue in my second approach?
Editing Note:
The correct answer is:
SELECT ST_AsText (ST_CENTROID(pol8.geom)) AS geom
FROM polygon8 AS pol8;
Thanks to iant.