OGRMERGE(1) GDAL OGRMERGE(1)

NAME

ogrmerge - Merge several vector datasets into a single one.

SYNOPSIS

ogrmerge [--help] [--help-general]
-o <out_dsname> <src_dsname> [<src_dsname>]...
[-f format] [-single] [-nln <layer_name_template>]
[-update | -overwrite_ds] [-append | -overwrite_layer]
[-src_geom_type <geom_type_name>[,<geom_type_name>]...]
[-dsco <NAME>=<VALUE>]... [-lco <NAME>=<VALUE>]...
[-s_srs <srs_def>] [-t_srs <srs_def> | -a_srs <srs_def>]
[-progress] [-skipfailures] [--help-general]

Options specific to the -single option:

[-field_strategy FirstLayer|Union|Intersection]
[-src_layer_field_name <name>]
[-src_layer_field_content <layer_name_template>]

DESCRIPTION

New in version 2.2.


ogrmerge takes as input several vector datasets, each of them having
one or several vector layers, and copies them into a target dataset.

There are essentially two modes:

+o the default one, where each input vector layer, is copied as a
separate layer into the target dataset

+o another one, activated with the -single switch, where the content
of all input vector layers is appended into a single target layer.
This assumes that the schema of those vector layers is more or less
the same.

Internally this generates a VRT -- Virtual Format file, and if the
output format is not VRT, final translation is done with ogr2ogr or
gdal.VectorTranslate(). So, for advanced uses, output to VRT,
potential manual editing of it and ogr2ogr can be done.

NOTE:
ogrmerge is a Python utility, and is only available if GDAL Python
bindings are available.

--help Show this help message and exit

--help-general
Gives a brief usage message for the generic GDAL commandline
options and exit.

-o <out_dsname>
Output dataset name. Required.

<src_dsname>
One or several input vector datasets. Required

-f <format>
Select the output format. Starting with GDAL 2.3, if not
specified, the format is guessed from the extension
(previously was ESRI Shapefile). Use the short format name

-single
If specified, all input vector layers will be merged into a
single one.

-nln <layer_name_template>
Name of the output vector layer (in single mode, and the
default is "merged"), or template to name the output vector
layers in default mode (the default value is {AUTO_NAME}). The
template can be a string with the following variables that
will be substituted with a value computed from the input layer
being processed:

+o {AUTO_NAME}: equivalent to {DS_BASENAME}_{LAYER_NAME} if
both values are different, or {LAYER_NAME} when they are
identical (case of shapefile).

+o {DS_NAME}: name of the source dataset

+o {DS_BASENAME}: base name of the source dataset

+o {DS_INDEX}: index of the source dataset

+o {LAYER_NAME}: name of the source layer

+o {LAYER_INDEX}: index of the source layer

-update
Open an existing dataset in update mode.

-overwrite_ds
Overwrite the existing dataset if it already exists (for file
based datasets)

-append
Open an existing dataset in update mode, and if output layers
already exist, append the content of input layers to them.

-overwrite_layer
Open an existing dataset in update mode, and if output layers
already exist, replace their content with the one of the input
layer.

-src_geom_type <geom_type_name>[,<geom_type_name>]...
Only take into account input layers whose geometry type match
the type(s) specified. Valid values for geom_type_name are
GEOMETRY, POINT, LINESTRING, POLYGON, MULTIPOINT,
MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION,
CIRCULARSTRING, CURVEPOLYGON, MULTICURVE, MULTISURFACE, CURVE,
SURFACE, TRIANGLE, POLYHEDRALSURFACE and TIN.

-dsco <NAME>=<VALUE>
Dataset creation option (format specific)

-lco <NAME>=<VALUE>
Layer creation option (format specific)

-a_srs <srs_def>
Assign an output SRS

-t_srs <srs_def>
Reproject/transform to this SRS on output

-s_srs <srs_def>
Override source SRS

-progress
Display progress on terminal. Only works if input layers have
the "fast feature count" capability.

-skipfailures
Continue after a failure, skipping the failed feature.

-field_strategy FirstLayer|Union|Intersection
Only used with -single. Determines how the schema of the
target layer is built from the schemas of the input layers.
May be FirstLayer to use the fields from the first layer
found, Union to use a super-set of all the fields from all
source layers, or Intersection to use a sub-set of all the
common fields from all source layers. Defaults to Union.

-src_layer_field_name <name>
Only used with -single. If specified, the schema of the target
layer will be extended with a new field 'name', whose content
is determined by -src_layer_field_content.

-src_layer_field_content <layer_name_template>
Only used with -single. If specified, the schema of the target
layer will be extended with a new field (whose name is given
by -src_layer_field_name, or 'source_ds_lyr' otherwise), whose
content is determined by layer_name_template. The syntax of
layer_name_template is the same as for -nln.

EXAMPLES

Create a VRT with a layer for each input shapefiles

ogrmerge -f VRT -o merged.vrt *.shp

Same, but creates a GeoPackage file

ogrmerge -f GPKG -o merged.gpkg *.shp

Concatenate the content of france.shp and germany.shp in merged.shp,
and adds a 'country' field to each feature whose value is 'france' or
'germany' depending where it comes from.

ogrmerge -single -o merged.shp france.shp germany.shp -src_layer_field_name country

AUTHOR

Even Rouault <even.rouault@spatialys.com>

COPYRIGHT

1998-2025

January 8, 2025 OGRMERGE(1)