Changes between Version 1 and Version 2 of FAQVector

Timestamp:

Apr 26, 2007, 9:16:03 AM (17 years ago)

Author:

maphew

Comment:

added wildcard merging of shapefiles

FAQVector

@@ -3 +3 @@
 [[PageOutline(2,,inline)]]
 
-''TBD''
+== How can I merge hundreds of shapefiles? ==
+
+Here's a bash script to bulk load a directory of shapefiles that have the same schema to postgis.  It could obviously be made smarter, but it seems to do the trick.
+{{{
+#!/bin/bash
+
+# let OGR create a table from one of the files
+ogr2ogr -f Postgresql PG:"host=smoke.hobu.net" -a_srs "EPSG:26915" -nln outputlayer first_input_shape.shp -overwrite -nlt POLYGON
+
+# delete all the data in the table we just created (but don't delete the table)
+ogrinfo PG:"host=smoke.hobu.net" -sql "delete  from outputlayer"
+
+# loop through all of the shapefiles in the directory and load them
+for i in $(ls *.shp); do
+  ogr2ogr -f Postgresql PG:"host=smoke.hobu.net" -a_srs " EPSG:26915" -nln outputlayer $i -update -append -skipfailures
+done 
+}}}
+
+This Windows cmd shell example merges multiple ''*wetlands*''shapefiles in the current directory to a single {{{merged\wetlands.shp}}} (double % to put in a script, {{{%f}}} --> {{{%%f}}}):
+{{{
+mkdir merged
+for %f in (*wetland*.shp) do (
+  (if not exist merged\wetlands.shp ogr2ogr -f "esri shapefile" merged\wetlands.shp %f) else (
+   ogr2ogr -f "esri shapefile" -update -append merged\wetlands.shp %f
+   )
+)
+}}}
+The trick is to use the first input to create a new shapefile, and thereafter only update and append. See the end of http://www.gdal.org/ogr/drv_shapefile.html