<answer>
<para>You can store point, line, polygon, multipoint, multiline,
multipolygon, and geometrycollections. These are specified in the
- Open GIS Well Known Text Format (with 3d extentions).</para>
+ Open GIS Well Known Text Format (with XYZ,XYM,XYZM extentions).</para>
</answer>
</qandaentry>
<filename>psql</filename> and try the following SQL:</para>
<programlisting>CREATE TABLE gtest ( ID int4, NAME varchar(20) );
-SELECT AddGeometryColumn('dbname','gtest','geom',-1,'LINESTRING',2);</programlisting>
+SELECT AddGeometryColumn('gtest','geom',-1,'LINESTRING',2);</programlisting>
<para>If the geometry column addition fails, you probably have not
loaded the PostGIS functions and objects into this database. See the
<itemizedlist>
<listitem>
- <para>POINT(0 0 0)</para>
+ <para>POINT(0 0) -- XY</para>
+ </listitem>
+
+ <listitem>
+ <para>POINT(0 0 0) -- XYZ</para>
+ </listitem>
+
+ <listitem>
+ <para>POINTM(0 0 0) -- XYM</para>
+ </listitem>
+
+ <listitem>
+ <para>POINT(0 0 0 0) -- XYZM</para>
</listitem>
<listitem>
</listitem>
</itemizedlist>
- <para>Note that in the examples above there are features with both
- 2-dimensional and 3-dimensional coordinates. PostGIS supports both 2D
- and 3D coordinates -- if you describe a feature with 2D coordinates when
- you insert it, the database will return that feature to you with 2D
- coordinates when you extract it. See the sections on the <link
- linkend="force_2d">force_2d()</link> and <link
- linkend="force_3d">force_3d()</link> functions for information on
- converting features to a particular coordinate dimension
+ <para>Note that in the examples above there are features with
+ 2-dimensional, 3-dimensional (XYZ,XYM) and 4-dimensional coordinates.
+ PostGIS supports 2D,3DZ,3DM and 4D coordinates -- if you describe a
+ feature with 2D coordinates when you insert it, the database will
+ return that feature to you with 2D coordinates when you extract it.
+ See the sections on the <link linkend="force_2d">force_2d()</link>,
+ <link linkend="force_3dz">force_3dz()</link>,
+ <link linkend="force_3dm">force_3dm()</link> and
+ <link linkend="force_4d">force_4d()</link> functions for information
+ on converting features to a particular coordinate dimension
representation.</para>
<sect2>
text representation which includes all the information necessary to
construct the object. Unlike the OpenGIS standard forms, it includes
the type, coordinate, <emphasis>and</emphasis> SRID information. The
- canonical form is the default form returned from a SELECT query. The
- example below shows the difference between the OGC standard and
+ canonical form is the default form returned from a SELECT query.
+ Since version 1.0.0 the canonical form is an HEX-encoded WKB with
+ an optional SRID=#; prefix.
+ The example below shows the difference between the OGC standard and
PostGIS canonical forms:</para>
- <programlisting>db=> SELECT AsText(geom) AS OGCGeom FROM thetable;
+ <programlisting>db=> SELECT AsText(geom) AS OGCGeom FROM SPATIALTABLE;
OGCGeom
-------------------------------------------------
-LINESTRING(-123.741378393049 48.9124018962261,-123.741587115639 48.9123981907507)
+POINT(-126.4 45.32)
(1 row)
db=> SELECT geom AS PostGISGeom FROM thetable;
PostGISGeom
-------------------------------------------------
-SRID=123;LINESTRING(-123.741378393049 48.9124018962261,-123.741587115639 48.9123981907507)
+SRID=312;01010000009A99999999995FC0295C8FC2F5A84640
(1 row)</programlisting>
</sect2>
</sect1>
<term>COORD_DIMENSION</term>
<listitem>
- <para>The spatial dimension (2 or 3 dimensional) of the
+ <para>The spatial dimension (2, 3 or 4 dimensional) of the
column.</para>
</listitem>
</varlistentry>
<listitem>
<para>The type of the spatial object. To restrict the spatial
column to a single type, use one of: POINT, LINESTRING, POLYGON,
- MULTPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION.
+ MULTPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION or
+ corresponding XYM versions POINTM, LINESTRINGM, POLYGONM,
+ MULTPOINTM, MULTILINESTRINGM, MULTIPOLYGONM, GEOMETRYCOLLECTIONM.
For heterogeneous (mixed-type) collections, you can use
"GEOMETRY" as the type.</para>
<listitem>
<para>Add a spatial column to the table using the OpenGIS
- "AddGeometryColumn" function. The syntax is:
- <command>AddGeometryColumn(<db_name>, <table_name>,
+ "AddGeometryColumn" function.</para>
+
+ <para>The syntax is:
+ <programlisting>AddGeometryColumn(<schema_name>, <table_name>,
+ <column_name>, <srid>, <type>,
+ <dimension>)</programlisting>
+
+ Or, using current schema:
+ <programlisting>AddGeometryColumn(<table_name>,
<column_name>, <srid>, <type>,
- <dimension>)</command>.</para>
+ <dimension>)</programlisting>
+ </para>
- <para>For example: <command>SELECT AddGeometryColumn('roads_db',
+ <para>Example1: <command>SELECT AddGeometryColumn('public',
+ 'roads_geom', 'geom', 423, 'LINESTRING', 2)</command></para>
+ <para>Example2: <command>SELECT AddGeometryColumn(
'roads_geom', 'geom', 423, 'LINESTRING', 2)</command></para>
</listitem>
</itemizedlist>
<para>Here is an example of SQL used to create a table and add a
- spatial column (assuming the db is "parks_db" and that an SRID of 128
+ spatial column (assuming that an SRID of 128
exists already):</para>
- <programlisting>CREATE TABLE PARKS ( PARK_ID int4, PARK_NAME varchar(128), PARK_DATE date, PARK_TYPE varchar(2) );
-SELECT AddGeometryColumn('parks_db', 'parks', 'park_geom', 128, 'MULTIPOLYGON', 2 );</programlisting>
+ <programlisting>CREATE TABLE parks ( PARK_ID int4, PARK_NAME varchar(128), PARK_DATE date, PARK_TYPE varchar(2) );
+SELECT AddGeometryColumn('parks', 'park_geom', 128, 'MULTIPOLYGON', 2 );</programlisting>
<para>Here is another example, using the generic "geometry" type and
the undefined SRID value of -1:</para>
- <programlisting>CREATE TABLE ROADS ( ROAD_ID int4, ROAD_NAME varchar(128) );
-SELECT AddGeometryColumn( 'roads_db', 'roads', 'roads_geom', -1, 'GEOMETRY', 3 );</programlisting>
+ <programlisting>CREATE TABLE roads ( ROAD_ID int4, ROAD_NAME varchar(128) );
+SELECT AddGeometryColumn( 'roads', 'roads_geom', -1, 'GEOMETRY', 3 );</programlisting>
</sect2>
</sect1>
<term>-k</term>
<listitem>
- <para>Keep column names upper case.</para>
+ <para>Keep idendifiers case (column, schema and attributes). Note that attributes in Shapefile are all UPPERCASE.</para>
</listitem>
</varlistentry>
<para>An example session using the loader to create an input file and
uploading it might look like this:</para>
- <programlisting># shp2pgsql shaperoads roadstable roadsdb > roads.sql
+ <programlisting># shp2pgsql shaperoads myschema.roadstable > roads.sql
# psql -d roadsdb -f roads.sql</programlisting>
<para>A conversion and upload can be done all in one step using UNIX
pipes:</para>
- <programlisting># shp2pgsql shaperoads roadstable roadsdb | psql -d roadsdb</programlisting>
+ <programlisting># shp2pgsql shaperoads myschema.roadstable | psql -d roadsdb</programlisting>
</sect2>
</sect1>
projects / postgis / commitdiff