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Dear Maxime <br><br>Thanks for your replay, i checked the polygons they are valid but they some time have z value.... St_isvalid drop z value.<br>below is the result when i use <br><pre>SELECT ST_Multi(ST_Union(the_geom)) FROM faces_obj;<br><br>"MULTIPOLYGON(((-14161.75 1941.76 2750,-14161.75 2241.76 2750,-9336.75 2241.76 2600,-9336.75 1941.76 2750,-14161.75 1941.76 2600)))"<br><br>these polygons are representing 3D box<br><br>i need them to be as one record (mutlipolygon insted of having them in as faces in several rows.<br><br>thank you <br><br>Ihab <br><br>Hello <br><br>I have the following table which has polygons, i need to create a multipolygon from these polygons<br>i tried to use the following query, but the result are strange<br><br>331;"POLYGON((-14161.75 2241.76 2600,-14161.75 2241.76 2900,-14161.75 1941.76 2900,-14161.75 1941.76 2600,-14161.75 2241.76 2600))"<br>338;"POLYGON((-9336.75 2241.76 2600,-9336.75 2241.76 2900,-9336.75 1941.76 2900,-9336.75 1941.76 2600,-9336.75 2241.76 2600))"<br>341;"POLYGON((-14161.75 1941.76 2600,-14161.75 2241.76 2600,-9336.75 2241.76 2600,-9336.75 1941.76 2600,-14161.75 1941.76 2600))"<br>344;"POLYGON((-14161.75 1941.76 2900,-14161.75 1941.76 2600,-9336.75 1941.76 2600,-9336.75 1941.76 2900,-14161.75 1941.76 2900))"<br>347;"POLYGON((-14161.75 2241.76 2900,-14161.75 1941.76 2900,-9336.75 1941.76 2900,-9336.75 2241.76 2900,-14161.75 2241.76 2900))"<br>350;"POLYGON((-14161.75 2241.76 2600,-14161.75 2241.76 2900,-9336.75 2241.76 2900,-9336.75 2241.76 2600,-14161.75 2241.76 2600))"<br>331;"POLYGON((-14161.75 2241.76 2600,-14161.75 2241.76 2900,-14161.75 1941.76 2900,-14161.75 1941.76 2600,-14161.75 2241.76 2600))"<br><br>SELECT asEwkt(ST_Multi(ST_Union(ARRAY(SELECT the_geom FROM faces_obj))));<br><br>the result<br><br>"MULTIPOLYGON(((-14161.75 1941.76 2750,-14161.75 2241.76 2750,-9336.75 2241.76 2600,-9336.75 1941.76 2750,-14161.75 1941.76 2600)))"<br><br>Kind regards<br><br>Ihab <br><br><br> <br><!--beginarticle--><br>eehab hamzeh wrote:<br>><i> SELECT asEwkt(ST_Multi(ST_Union(ARRAY(SELECT the_geom FROM faces_obj))));<br></i><br>Hi,<br><br>Did you try to simply do :<br><br>SELECT ST_Multi(ST_Union(the_geom)) FROM faces_obj;<br><br>The ST_Union function will merge polygons if it is possible.<br><br>BTW, some of you polygons are invalid (check them with ST_IsValid). For <br>example the first one :<br><br>><i> # SELECT ST_IsValid('POLYGON((-14161.75 2241.76 2600,-14161.75 2241.76 2900,-14161.75 1941.76 2900,-14161.75 1941.76 2600,-14161.75 2241.76 2600))');<br></i>><i> NOTICE: Too few points in geometry component at or near point -14161.8 2241.76 2600<br></i>><i> st_isvalid <br></i>><i> ------------<br></i>><i> f<br></i><br>-- <br>Maxime<br><br><br></pre><br><br><img alt=""><img alt=""><img alt=""><br><br> <br /><hr />Windows Live™: Keep your life in sync. <a href='http://windowslive.com/explore?ocid=TXT_TAGLM_WL_t1_allup_explore_012009' target='_new'>Check it out!</a></body>
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