# ogr2ogr¶

Converts simple features data between file formats.

## Synopsis¶

ogr2ogr [--help-general] [-skipfailures] [-append] [-update]
[-select field_list] [-where restricted_where|\@filename]
[-progress] [-sql <sql statement>|\@filename] [-dialect dialect]
[-preserve_fid] [-fid FID] [-limit nb_features]
[-spat xmin ymin xmax ymax] [-spat_srs srs_def] [-geomfield field]
[-a_srs srs_def] [-t_srs srs_def] [-s_srs srs_def] [-ct string]
[-f format_name] [-overwrite] [[-dsco NAME=VALUE] ...]
dst_datasource_name src_datasource_name
[-lco NAME=VALUE] [-nln name]
[-nlt type|PROMOTE_TO_MULTI|CONVERT_TO_LINEAR|CONVERT_TO_CURVE]
[-dim XY|XYZ|XYM|XYZM|2|3|layer_dim] [layer [layer ...]]

[-gt n]
[[-oo NAME=VALUE] ...] [[-doo NAME=VALUE] ...]
[-clipsrc [xmin ymin xmax ymax]|WKT|datasource|spat_extent]
[-clipsrcsql sql_statement] [-clipsrclayer layer]
[-clipsrcwhere expression]
[-clipdst [xmin ymin xmax ymax]|WKT|datasource]
[-clipdstsql sql_statement] [-clipdstlayer layer]
[-clipdstwhere expression]
[-wrapdateline] [-datelineoffset val]
[[-simplify tolerance] | [-segmentize max_dist]]
[-relaxedFieldNameMatch] [-forceNullable] [-unsetDefault]
[-fieldTypeToString All|(type1[,type2]*)] [-unsetFieldWidth]
[-mapFieldType type1|All=type2[,type3=type4]*]
[-fieldmap identity | index1[,index2]*]
[-splitlistfields] [-maxsubfields val]
[-explodecollections] [-zfield field_name]
[-gcp ungeoref_x ungeoref_y georef_x georef_y [elevation]]* [-order n | -tps]
[-nomd] [-mo "META-TAG=VALUE"]* [-noNativeData]


## Description¶

ogr2ogr can be used to convert simple features data between file formats. It can also perform various operations during the process, such as spatial or attribute selection, reducing the set of attributes, setting the output coordinate system or even reprojecting the features during translation.

-f <format_name>

Output file format name, e.g. ESRI Shapefile, MapInfo File, PostgreSQL. Starting with GDAL 2.3, if not specified, the format is guessed from the extension (previously was ESRI Shapefile).

-append

Append to existing layer instead of creating new

-overwrite

Delete the output layer and recreate it empty

-update

Open existing output datasource in update mode rather than trying to create a new one

-select <field_list>

Comma-delimited list of fields from input layer to copy to the new layer. A field is skipped if mentioned previously in the list even if the input layer has duplicate field names. (Defaults to all; any field is skipped if a subsequent field with same name is found.) Geometry fields can also be specified in the list.

Note this setting cannot be used together with -append. To control the selection of fields when appending to a layer, use -fieldmap or -sql.

-progress

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

-sql <sql_statement>

SQL statement to execute. The resulting table/layer will be saved to the output. Starting with GDAL 2.1, the @filename syntax can be used to indicate that the content is in the pointed filename.

-dialect <dialect>

SQL dialect. In some cases can be used to use (unoptimized) OGR SQL instead of the native SQL of an RDBMS by passing OGRSQL. The “SQLITE” dialect can also be used with any datasource.

-where restricted_where

Attribute query (like SQL WHERE). Starting with GDAL 2.1, the @filename syntax can be used to indicate that the content is in the pointed filename.

-skipfailures

Continue after a failure, skipping the failed feature.

-spat <xmin> <ymin> <xmax> <ymax>

spatial query extents, in the SRS of the source layer(s) (or the one specified with -spat_srs). Only features whose geometry intersects the extents will be selected. The geometries will not be clipped unless -clipsrc is specified.

-spat_srs <srs_def>

Override spatial filter SRS.

-geomfield <field>

Name of the geometry field on which the spatial filter operates on.

-dsco NAME=VALUE

Dataset creation option (format specific)

-lco NAME=VALUE

Layer creation option (format specific)

-nln <name>

Assign an alternate name to the new layer

-nlt <type>

Define the geometry type for the created layer. One of NONE, GEOMETRY, POINT, LINESTRING, POLYGON, GEOMETRYCOLLECTION, MULTIPOINT, MULTIPOLYGON, MULTILINESTRING, CIRCULARSTRING, COMPOUNDCURVE, CURVEPOLYGON, MULTICURVE, and MULTISURFACE non-linear geometry types. Add Z, M, or ZM to the type name to specify coordinates with elevation, measure, or elevation and measure. PROMOTE_TO_MULTI can be used to automatically promote layers that mix polygon or multipolygons to multipolygons, and layers that mix linestrings or multilinestrings to multilinestrings. Can be useful when converting shapefiles to PostGIS and other target drivers that implement strict checks for geometry types. CONVERT_TO_LINEAR can be used to to convert non-linear geometry types into linear geometry types by approximating them, and CONVERT_TO_CURVE to promote a non-linear type to its generalized curve type (POLYGON to CURVEPOLYGON, MULTIPOLYGON to MULTISURFACE, LINESTRING to COMPOUNDCURVE, MULTILINESTRING to MULTICURVE). Starting with version 2.1 the type can be defined as measured (“25D” remains as an alias for single “Z”). Some forced geometry conversions may result in invalid geometries, for example when forcing conversion of multi-part multipolygons with -nlt POLYGON, the resulting polygon will break the Simple Features rules.

-dim <val>

Force the coordinate dimension to val (valid values are XY, XYZ, XYM, and XYZM - for backwards compatibility 2 is an alias for XY and 3 is an alias for XYZ). This affects both the layer geometry type, and feature geometries. The value can be set to layer_dim to instruct feature geometries to be promoted to the coordinate dimension declared by the layer. Support for M was added in GDAL 2.1.

-a_srs <srs_def>

Assign an output SRS. Srs_def can be a full WKT definition (hard to escape properly), or a well known definition (i.e. EPSG:4326) or a file with a WKT definition.

-t_srs <srs_def>

Reproject/transform to this SRS on output.

-s_srs <srs_def>

Override source SRS.

-ct <string>

A PROJ string (single step operation or multiple step string starting with +proj=pipeline), a WKT2 string describing a CoordinateOperation, or a urn:ogc:def:coordinateOperation:EPSG::XXXX URN overriding the default transformation from the source to the target CRS. It must take into account the axis order of the source and target CRS.

New in version 3.0.

-preserve_fid

Use the FID of the source features instead of letting the output driver automatically assign a new one (for formats that require an FID). If not in append mode, this behaviour is the default if the output driver has a FID layer creation option, un which case the name of the source FID column will be used and source feature IDs will be attempted to be preserved. This behaviour can be disabled by setting -unsetFid.

-fid fid

If provided, only the feature with the specified feature id will be processed. Operates exclusive of the spatial or attribute queries. Note: if you want to select several features based on their feature id, you can also use the fact the ‘fid’ is a special field recognized by OGR SQL. So, -where “fid in (1,3,5)” would select features 1, 3 and 5.

-limit nb_features

Limit the number of features per layer.

-oo NAME=VALUE

Input dataset open option (format specific).

-doo NAME=VALUE

Destination dataset open option (format specific), only valid in -update mode.

-gt n

Group n features per transaction (default 20000). Increase the value for better performance when writing into DBMS drivers that have transaction support. n can be set to unlimited to load the data into a single transaction.

-ds_transaction

Force the use of a dataset level transaction (for drivers that support such mechanism), especially for drivers such as FileGDB that only support dataset level transaction in emulation mode.

-clipsrc [xmin ymin xmax ymax]|WKT|datasource|spat_extent

Clip geometries to the specified bounding box (expressed in source SRS), WKT geometry (POLYGON or MULTIPOLYGON), from a datasource or to the spatial extent of the -spa.. option if you use the spat_extent keyword. When specifying a datasource, you will generally want to use it in combination of the -clipsrclayer, -clipsrcwhere or -clipsrcsql options

-clipsrcsql <sql_statement>

Select desired geometries using an SQL query instead.

-clipsrclayer <layername>

Select the named layer from the source clip datasource.

-clipsrcwhere <expression>

Restrict desired geometries based on attribute query.

-clipdst <xmin> <ymin> <xmax> <ymax>

Clip geometries after reprojection to the specified bounding box (expressed in dest SRS), WKT geometry (POLYGON or MULTIPOLYGON) or from a datasource. When specifying a datasource, you will generally want to use it in combination of the -clipdstlayer, -clipdstwhere or -clipdstsq.. options

-clipdstsql <sql_statement>

Select desired geometries using an SQL query instead.

-clipdstlayer <layername>

Select the named layer from the destination clip datasource.

-clipdstwhere <expression>

Restrict desired geometries based on attribute query.

-wrapdateline

Split geometries crossing the dateline meridian (long. = +/- 180deg)

-datelineoffset

Offset from dateline in degrees (default long. = +/- 10deg, geometries within 170deg to -170deg will be split)

-simplify <tolerance>

Distance tolerance for simplification. Note: the algorithm used preserves topology per feature, in particular for polygon geometries, but not for a whole layer.

-segmentize <max_dist>

Maximum distance between 2 nodes. Used to create intermediate points.

-fieldTypeToString type1,...

Converts any field of the specified type to a field of type string in the destination layer. Valid types are : Integer, Integer64, Real, String, Date, Time, DateTime, Binary, IntegerList, Integer64List, RealList, StringList. Special value All can be used to convert all fields to strings. This is an alternate way to using the CAST operator of OGR SQL, that may avoid typing a long SQL query. Note that this does not influence the field types used by the source driver, and is only an afterwards conversion.

-mapFieldType srctype|All=dsttype,...

Converts any field of the specified type to another type. Valid types are : Integer, Integer64, Real, String, Date, Time, DateTime, Binary, IntegerList, Integer64List, RealList, StringList. Types can also include subtype between parenthesis, such as Integer(Boolean), Real(Float32), … Special value All can be used to convert all fields to another type. This is an alternate way to using the CAST operator of OGR SQL, that may avoid typing a long SQL query. This is a generalization of -fieldTypeToString. Note that this does not influence the field types used by the source driver, and is only an afterwards conversion.

-unsetFieldWidth

Set field width and precision to 0.

-splitlistfields

Split fields of type StringList, RealList or IntegerList into as many fields of type String, Real or Integer as necessary.

-maxsubfields <val>

To be combined with -splitlistfields to limit the number of subfields created for each split field.

-explodecollections

Produce one feature for each geometry in any kind of geometry collection in the source file

-zfield <field_name>

Uses the specified field to fill the Z coordinate of geometries.

-gcp <ungeoref_x> <ungeoref_y> <georef_x> <georef_y> <elevation>

Add the indicated ground control point. This option may be provided multiple times to provide a set of GCPs.

-order <n>

Order of polynomial used for warping (1 to 3). The default is to select a polynomial order based on the number of GCPs.

-tps

Force use of thin plate spline transformer based on available GCPs.

-fieldmap

Specifies the list of field indexes to be copied from the source to the destination. The (n)th value specified in the list is the index of the field in the target layer definition in which the n(th) field of the source layer must be copied. Index count starts at zero. To omit a field, specify a value of -1. There must be exactly as many values in the list as the count of the fields in the source layer. We can use the ‘identity’ setting to specify that the fields should be transferred by using the same order. This setting should be used along with the -append setting.

-addfields

This is a specialized version of -append. Contrary to -append, -addfields has the effect of adding, to existing target layers, the new fields found in source layers. This option is useful when merging files that have non-strictly identical structures. This might not work for output formats that don’t support adding fields to existing non-empty layers. Note that if you plan to use -addfields, you may need to combine it with -forceNullable, including for the initial import.

-relaxedFieldNameMatch

Do field name matching between source and existing target layer in a more relaxed way if the target driver has an implementation for it.

-forceNullable

Do not propagate not-nullable constraints to target layer if they exist in source layer.

-unsetDefault

Do not propagate default field values to target layer if they exist in source layer.

-unsetFid

Can be specify to prevent the name of the source FID column and source feature IDs from being re-used for the target layer. This option can for example be useful if selecting source features with a ORDER BY clause.

-nomd

To disable copying of metadata from source dataset and layers into target dataset and layers, when supported by output driver.

-mo META-TAG=VALUE

Passes a metadata key and value to set on the output dataset, when supported by output driver.

-noNativeData

To disable copying of native data, i.e. details of source format not captured by OGR abstraction, that are otherwise preserved by some drivers (like GeoJSON) when converting to same format.

New in version 2.1.

## Performance Hints¶

When writing into transactional DBMS (SQLite/PostgreSQL,MySQL, etc…), it might be beneficial to increase the number of INSERT statements executed between BEGIN TRANSACTION and COMMIT TRANSACTION statements. This number is specified with the -gt option. For example, for SQLite, explicitly defining -gt 65536 ensures optimal performance while populating some table containing many hundreds of thousands or millions of rows. However, note that -skipfailures overrides -gt and sets the size of transactions to 1.

For PostgreSQL, the PG_USE_COPY config option can be set to YES for a significant insertion performance boost. See the PG driver documentation page.

More generally, consult the documentation page of the input and output drivers for performance hints.

## C API¶

This utility is also callable from C with GDALVectorTranslate().

## Examples¶

Example appending to an existing layer (both -update and -append flags need to be used):

ogr2ogr -update -append -f PostgreSQL PG:dbname=warmerda abc.tab


Example reprojecting from ETRS_1989_LAEA_52N_10E to EPSG:4326 and clipping to a bounding box:

ogr2ogr -wrapdateline -t_srs EPSG:4326 -clipdst -5 40 15 55 france_4326.shp europe_laea.shp


Example for using the -fieldmap setting. The first field of the source layer is used to fill the third field (index 2 = third field) of the target layer, the second field of the source layer is ignored, the third field of the source layer used to fill the fifth field of the target layer.

ogr2ogr -append -fieldmap 2,-1,4 dst.shp src.shp


More examples are given in the individual format pages.