From: Bborie Park <bkpark at ucdavis.edu>
Date: Mon, 29 Oct 2012 18:56:41 +0000 (+0000)
Subject: Added UpdateRasterSRID() as per ticket #739
X-Git-Tag: 2.1.0beta2~445
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=19dc276d02ce187babf1b96f7e5013a7d5b2d815;p=postgis

Added UpdateRasterSRID() as per ticket #739

git-svn-id: http://svn.osgeo.org/postgis/trunk@10581 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index 80213263a..4b9c59a68 100644
--- a/NEWS
+++ b/NEWS
@@ -42,6 +42,7 @@ PostGIS 2.1.0
     a band using a set of geometries and corresponding values in one call
     (Bborie Park / UC Davis)
   - ST_Tile(raster) to break up a raster into tiles (Bborie Park / UC Davis)
+  - #739, UpdateRasterSRID()
 
 * Enhancements *
   - #823,  tiger geocoder: Make loader_generate_script download portion 
diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml
index fae54f717..a4866b00c 100644
--- a/doc/reference_raster.xml
+++ b/doc/reference_raster.xml
@@ -976,6 +976,51 @@ WHERE short_name = 'GTiff') As g;
 	  </refsection>
 	</refentry>
 
+		<refentry id="RT_UpdateRasterSRID">
+			<refnamediv>
+				<refname>UpdateRasterSRID</refname>
+				<refpurpose>
+					Change the SRID of all rasters in the user-specified column and table.
+				</refpurpose>
+			</refnamediv>
+
+			<refsynopsisdiv>
+				<funcsynopsis>
+
+					<funcprototype>
+						<funcdef>raster <function>UpdateRasterSRID</function></funcdef>
+						<paramdef><type>name </type> <parameter>schema_name</parameter></paramdef>
+						<paramdef><type>name </type> <parameter>table_name</parameter></paramdef>
+						<paramdef><type>name </type> <parameter>column_name</parameter></paramdef>
+						<paramdef><type>integer </type> <parameter>new_srid</parameter></paramdef>
+					</funcprototype>
+
+					<funcprototype>
+						<funcdef>raster <function>UpdateRasterSRID</function></funcdef>
+						<paramdef><type>name </type> <parameter>table_name</parameter></paramdef>
+						<paramdef><type>name </type> <parameter>column_name</parameter></paramdef>
+						<paramdef><type>integer </type> <parameter>new_srid</parameter></paramdef>
+					</funcprototype>
+
+				</funcsynopsis>
+			</refsynopsisdiv>
+
+			<refsection>
+				<title>Description</title> 
+
+				<para>
+					Change the SRID of all rasters in the user-specified column and table. The function will drop all appropriate column constraints (extent, alignment and SRID) before changing the SRID of the specified column's rasters.
+				</para>
+
+				<note>
+					<para>
+						The data (band pixel values) of the rasters are not touched by this function.  Only the raster's metadata is changed.
+					</para>
+				</note>
+
+				<para>Availability: 2.1.0</para>
+			</refsection> 
+		</refentry>
   </sect1>
   
 	<sect1 id="Raster_Constructors">
diff --git a/raster/rt_pg/rtpostgis.sql.in.c b/raster/rt_pg/rtpostgis.sql.in.c
index 68442d781..2c072142d 100644
--- a/raster/rt_pg/rtpostgis.sql.in.c
+++ b/raster/rt_pg/rtpostgis.sql.in.c
@@ -7120,6 +7120,101 @@ CREATE OR REPLACE FUNCTION DropOverviewConstraints (
 	LANGUAGE 'sql' VOLATILE STRICT
 	COST 100;
 
+------------------------------------------------------------------------------
+-- UpdateRasterSRID
+------------------------------------------------------------------------------
+
+CREATE OR REPLACE FUNCTION _UpdateRasterSRID(
+	schema_name name, table_name name, column_name name,
+	new_srid integer
+)
+	RETURNS boolean
+	AS $$
+	DECLARE
+		fqtn text;
+		schema name;
+		sql text;
+		srid integer;
+	BEGIN
+		-- validate schema
+		schema := NULL;
+		IF length($1) > 0 THEN
+			sql := 'SELECT nspname FROM pg_namespace '
+				|| 'WHERE nspname = ' || quote_literal($1)
+				|| 'LIMIT 1';
+			EXECUTE sql INTO schema;
+
+			IF schema IS NULL THEN
+				RAISE EXCEPTION 'The value provided for schema is invalid';
+				RETURN FALSE;
+			END IF;
+		END IF;
+
+		IF schema IS NULL THEN
+			sql := 'SELECT n.nspname AS schemaname '
+				|| 'FROM pg_catalog.pg_class c '
+				|| 'JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace '
+				|| 'WHERE c.relkind = ' || quote_literal('r')
+				|| ' AND n.nspname NOT IN (' || quote_literal('pg_catalog')
+				|| ', ' || quote_literal('pg_toast')
+				|| ') AND pg_catalog.pg_table_is_visible(c.oid)'
+				|| ' AND c.relname = ' || quote_literal($2);
+			EXECUTE sql INTO schema;
+
+			IF schema IS NULL THEN
+				RAISE EXCEPTION 'The table % does not occur in the search_path', quote_literal($2);
+				RETURN FALSE;
+			END IF;
+		END IF;
+
+		-- clamp SRID
+		IF new_srid < 0 THEN
+			srid := ST_SRID('POINT EMPTY'::geometry);
+			RAISE NOTICE 'SRID % converted to the officially unknown SRID %', new_srid, srid;
+		ELSE
+			srid := new_srid;
+		END IF;
+
+		-- drop SRID, extent, alignment constraints
+		PERFORM DropRasterConstraints(schema, $2, $3, 'extent', 'alignment', 'srid');
+
+		fqtn := '';
+		IF length($1) > 0 THEN
+			fqtn := quote_ident($1) || '.';
+		END IF;
+		fqtn := fqtn || quote_ident($2);
+
+		-- update SRID
+		sql := 'UPDATE ' || fqtn ||
+			' SET ' || quote_ident($3) ||
+			' = ST_SetSRID(' || quote_ident($3) ||
+			'::raster, ' || srid || ')';
+		RAISE NOTICE 'sql = %', sql;
+		EXECUTE sql;
+
+		-- add SRID constraint
+		PERFORM AddRasterConstraints(schema, $2, $3, 'srid', 'extent', 'alignment');
+
+		RETURN TRUE;
+	END;
+	$$ LANGUAGE 'plpgsql' VOLATILE;
+
+CREATE OR REPLACE FUNCTION UpdateRasterSRID(
+	schema_name name, table_name name, column_name name,
+	new_srid integer
+)
+	RETURNS boolean
+	AS $$ SELECT _UpdateRasterSRID($1, $2, $3, $4) $$
+	LANGUAGE 'sql' VOLATILE STRICT;
+
+CREATE OR REPLACE FUNCTION UpdateRasterSRID(
+	table_name name, column_name name,
+	new_srid integer
+)
+	RETURNS boolean
+	AS $$ SELECT _UpdateRasterSRID('', $1, $2, $3) $$
+	LANGUAGE 'sql' VOLATILE STRICT;
+
 -------------------------------------------------------------------
 --  END
 -------------------------------------------------------------------