From 7cb9653c8b19494e14d56c6eb2ce8a11a072892b Mon Sep 17 00:00:00 2001 From: Regina Obe Date: Sat, 10 Dec 2011 16:55:38 +0000 Subject: [PATCH] describe the example a bit better for ST_AddBand multi-band example git-svn-id: http://svn.osgeo.org/postgis/trunk@8346 b70326c6-7e19-0410-871a-916f4a2858ee --- doc/reference_raster.xml | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml index c5d08fcba..acf7d2f3d 100644 --- a/doc/reference_raster.xml +++ b/doc/reference_raster.xml @@ -1155,10 +1155,15 @@ FROM (SELECT ST_MetaData(rast) As rmd Examples: Multi-Band versions - -- Aggregate a bunch of rasters 1st bands into a single band rast --- not the rasters must be aligned. -SELECT ST_AddBand(NULL, array_agg(rast), 1 ) As rast - FROM some_rast_table; + -- Aggregate the 1st band of a table of like rasters into a single raster +-- with as many bands as there are test_types and as many rows as there are time_slots +-- NOTE: The ORDER BY test_type is only supported in PostgreSQL 9.0 +-- for 8.4 and below it usually works to order your data in a subselect (but not guaranteed) +-- The resulting raster will have a band for each test_type alphabetical by test_type +-- For mouse lovers: No mice were harmed in this exercise +SELECT rabbit, ST_AddBand(NULL, array_agg(rast ORDER BY test_type), 1 ) As rast + FROM mice_studies + GROUP BY mice; -- 2.40.0