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NAME  - Imports vector data into a GRASS vector map using OGR library.


       vector, import, OGR, topology, geometry, snapping, create location

SYNOPSIS --help    [-flc2tojrewi]    input=string     [gdal_config=string]      [gdal_doo=string]
       [layer=string[,string,...]]                                                  [output=name]
       [spatial=xmin,ymin,xmax,ymax[,xmin,ymin,xmax,ymax,...]]                  [where=sql_query]
       [min_area=float]       [type=string[,string,...]]       [snap=float]       [location=name]
       [columns=name[,name,...]]       [encoding=string]       [key=string]       [geometry=name]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

           List supported OGR formats and exit

           List available OGR layers in data source and exit

           Do not clean polygons (not recommended)

           Force 2D output even if input is 3D
           Useful if input is 3D but all z coordinates are identical

           Do not create attribute table

           Override projection check (use current location’s projection)
           Assume that the dataset has the same projection as the current location

           Perform projection check only and exit

           Limit import to the current region

           Extend region extents based on new dataset
           Also updates the default region if in the PERMANENT mapset

           Change column names to lowercase characters

           Create the location specified by the "location" parameter and exit. Do not import  the
           vector data.

           Allow output files to overwrite existing files

           Print usage summary

           Verbose module output

           Quiet module output

           Force launching GUI dialog

       input=string [required]
           Name of OGR datasource to be imported
           ESRI Shapefile: directory containing shapefiles
           MapInfo File: directory containing mapinfo files

           GDAL configuration options
           Comma-separated list of key=value pairs

           GDAL dataset open options
           Comma-separated list of key=value pairs

           OGR layer name. If not given, all available layers are imported
           ESRI Shapefile: shapefile name
           MapInfo File: mapinfo file name

           Name for output vector map

           Import subregion only
           Format: xmin,ymin,xmax,ymax - usually W,S,E,N

           WHERE conditions of SQL statement without ’where’ keyword
           Example: income < 1000 and population >= 10000

           Minimum size of area to be imported (square meters)
           Smaller areas and islands are ignored. Should be greater than snap^2
           Default: 0.0001

           Optionally change default input type
           Options: point, line, boundary, centroid
           point: import area centroids as points
           line: import area boundaries as lines
           boundary: import lines as area boundaries
           centroid: import points as centroids

           Snapping threshold for boundaries (map units)
           ’-1’ for no snap
           Default: -1

           Name for new location to create

           List  of column names to be used instead of original names, first is used for category

           Encoding value for attribute data
           Overrides encoding interpretation, useful when importing ESRI Shapefile

           Name of column used for categories
           If not given, categories are generated as unique values and stored in ’cat’ column

           Name of geometry column
           If not given, all geometry columns from the input are used

DESCRIPTION imports vector data from files and database  connections  supported  by  the  OGR
       library) into the current location and mapset.

       If  the  layer  parameter  is not given, all available OGR layers are imported as separate
       GRASS layers into one GRASS vector map. If several OGR layer names are  given,  all  these
       layers are imported as separate GRASS layers into one GRASS vector map.

       The  optional  spatial parameter defines spatial query extents.  This parameter allows the
       user to restrict the region to a spatial subset  while  importing  the  data.  All  vector
       features  completely or partially falling into this rectangle subregion are imported.  The
       -r current region flag is identical, but uses the current region settings as  the  spatial
       bounds (see g.region).

   Supported Vector Formats  uses  the  OGR library which supports various vector data formats including ESRI
       Shapefile, Mapinfo File, UK .NTF, SDTS, TIGER, IHO S-57 (ENC), DGN, GML, GPX, AVCBin, REC,
       Memory, OGDI, and PostgreSQL, depending on the local OGR installation. For details see the
       OGR web site. The -f prints a list of the vector formats supported  by  the  system’s  OGR
       (Simple  Features Library). The OGR (Simple Features Library) is part of the GDAL library,
       hence GDAL needs to be installed to use

       The list of actually supported formats can be printed by -f flag.

   Topology cleaning
       Topology cleaning on areas is automatically performed, but may fail in special  cases.  In
       these cases, a snap threshold value is estimated from the imported vector data and printed
       out at the end. The vector data can  then  be  imported  again  with  the  suggested  snap
       threshold value which is incremented by powers of 10 until either an estimated upper limit
       for the threshold value is reached or the topology cleaning on areas  was  successful.  In
       some cases, manual cleaning might be required or areas are truly overlapping, e.g. buffers
       created with non-topological software.

       The min_area threshold value is being specified  as  area  size  in  map  units  with  the
       exception  of latitude-longitude locations in which it is being specified solely in square

       The snap threshold value is used to snap boundary vertices to each other if  the  distance
       in map units between two vertices is not larger than the threshold. Snapping is by default
       disabled with -1. See also the v.clean manual.

   Overlapping polygons
       When importing overlapping polygons, the overlapping parts  will  become  new  areas  with
       multiple  categories,  one  unique category for each original polygon. An original polygon
       will thus be converted to multiple areas with the same  shared  category.  These  multiple
       areas will therefore also link to the same entry in the attribute table. A single category
       value may thus refer to  multiple  non-overlapping  areas  which  together  represent  the
       original  polygon  overlapping with another polygon. The original polygon can be recovered
       by using v.extract with the desired category value or where statement and the -d  flag  to
       dissolve common boundaries.

Location Creation attempts to preserve projection information when importing datasets if the source
       format includes projection information, and  if  the  OGR  driver  supports  it.   If  the
       projection  of  the  source  dataset does not match the projection of the current location will report an error message ("Projection of dataset does  not  appear  to  match
       current location").

       If  the user wishes to ignore the difference between the apparent coordinate system of the
       source data and the current location, they may pass the -o flag to override the projection

       If  the user wishes to import the data with the full projection definition, it is possible
       to have automatically create a new location based on the projection  and  extents
       of  the  file  being read. This is accomplished by passing the name to be used for the new
       location via the location parameter.  Upon completion of the command, a new location  will
       have  been  created  (with  only  a  PERMANENT  mapset), and the vector map will have been
       imported with the indicated output name into the PERMANENT mapset.

       An interesting wrapper command around is v.import which  reprojects  (if  needed)
       the vector dataset during import to the projection of the current location.


   Table column names: supported characters
       The  characters which are eligible for table column names are limited by the SQL standard.
       Supported are:
       This means that SQL neither supports ’.’ (dots) nor ’-’ (minus) nor ’#’  in  table  column
       names. Also a table name must start with a character, not a number.  converts ’.’, ’-’ and ’#’ to ’_’ (underscore) during import. The -w flag changes
       capital column names to lowercase characters as a convenience  for  SQL  usage  (lowercase
       column  names  avoid the need to quote them if the attribute table is stored in a SQL DBMS
       such as PostgreSQL). The columns parameter is used  to  define  new  column  names  during

       The DBF database specification limits column names to 10 characters.  If the default DB is
       set to DBF and the input data contains longer column/field names, they will be  truncated.
       If  this  results  in  multiple  columns  with the same name then will produce an
       error.  In this case you will either have to modify  the  input  data  or  use’s
       columns  parameter  to rename columns to something unique. (hint: copy and modify the list
       given with the error message).  Alternatively, change the local DB with db.connect.

   File encoding
       When importing ESRI Shapefiles the OGR library tries to  read  the  LDID/codepage  setting
       from  the  .dbf  file  and use it to translate string fields to UTF-8. LDID "87 / 0x57" is
       treated as ISO8859_1 which may not be appropriate for many languages. Unfortunately it  is
       not clear what other values may be appropriate (see example below). To change encoding the
       user can set up SHAPE_ENCODING environmental variable or simply to define  encoding  value
       using encoding parameter. Note that recoding support is new for GDAL/OGR 1.9.0.

       Value  for encoding also affects text recoding when importing DXF files. For other formats
       has encoding value no effect.

   Defining the key column
       Option key specifies the column name used for feature  categories.  This  column  must  be
       integer.  If not specified, categories numbers are generated starting with 1 and stored in
       the column named "cat".

   Supports of multiple geometry columns
       Starting with GDAL 1.11 the library supports multiple geometry columns in OGR. By  default reads all geometry columns from given layer. The user can choose desired geometry
       column by geometry option, see example below.

   Latitude-longitude data: Vector postprocessing after import
       For vector data like a grid, horizontal lines need to be  broken  at  their  intersections
       with vertical lines (v.clean ... tool=break).


       The command imports various vector formats:

   SHAPE files input=/home/user/shape_data/test_shape.shp output=grass_map
       Alternate method: input=/home/user/shape_data layer=test_shape output=grass_map
       Define  encoding  value  for  attribute  data (in this example we expect attribute data in
       Windows-1250 encoding; ie. in Central/Eastern European languages that  use  Latin  script,
       Microsoft Windows encoding). input=/home/user/shape_data/test_shape.shp output=grass_map encoding=cp1250

   MapInfo files input=./ layer=mapinfo_test output=grass_map

   Arc Coverage
       We import the Arcs and Label points, the module takes care to build areas. input=gemeinden layer=LAB,ARC type=centroid,boundary output=mymap

   E00 file
       See also

       First  we  have to convert the E00 file to an Arc Coverage with ’avcimport’ (AVCE00 tools,
       use e00conv first in case that avcimport fails):
       avcimport e00file coverage input=coverage layer=LAB,ARC type=centroid,boundary output=mymap

   SDTS files
       You have to select the CATD file. input=CITXCATD.DDF output=cities

   TIGER files input=input/2000/56015/ layer=CompleteChain,PIP output=t56015_all \
       type=boundary,centroid snap=-1

   PostGIS tables
       Import polygons as areas: input="PG:host=localhost dbname=postgis user=postgres" layer=polymap \
       output=polygons type=boundary,centroid
       If the table containing the polygons are in a specific schema, you can use: input="PG:host=localhost dbname=postgis user=postgres" \
       layer=myschema.polymap \
       output=polygons type=boundary,centroid
       Generally, just follows the format-specific syntax defined by the OGR library.

   OpenStreetMap (OSM)
       OSM data are available in .osm (XML based) and .pbf (optimized binary) formats.  The  .pbf
       format  is  recommended  because  file  sizes  are smaller. The OSM driver will categorize
       features into 5 layers :

           ·   points: "node" features that have significant tags attached.

           ·   lines: "way" features that are recognized as non-area.

           ·   multilinestrings:  "relation"  features  that  form   a   multilinestring(type   =
               ’multilinestring’ or type = ’route’).

           ·   multipolygons: "relation" features that form a multipolygon (type = ’multipolygon’
               or type = ’boundary’), and "way" features that are recognized as area.

           ·   other_relations: "relation" features that do  not  belong  to  any  of  the  above
       It  is  recommended  to  import one layer at a time, and to select features with the where
       option, e.g. to import roads, use where="highway <> ’’"
       i.e. the OSM tag highway must be set.

       When importing administrative boundaries from OSM, it is  important  to  not  only  select
       administrative  boundaries,  but  also  the admin level to be imported (valid range is 1 -
       11), e.g. with where="boundary = ’administrative’ and admin_level = ’1’"

       The OSM topological model differs from the  GRASS  topological  model.  OSM  topologically
       correct  connections  of  lines can be on all vertices of a line. During import, lines are
       automatically split at those vertices where an OSM connection to another line exists.

       Import of OSM data  requires  a  configuration  file,  defined  with  the  OSM_CONFIG_FILE
       configuration  option.  In  the  data  folder  of  the  GDAL  distribution, you can find a
       osmconf.ini file that can be customized to fit your needs. See OSM map features  for  keys
       and their values. You should set "other_tags=no" to avoid problems with import or querying
       the imported vector. Once a OSM_CONFIG_FILE has been created, OSM  data  can  be  imported
       with e.g.
       export OSM_CONFIG_FILE=/path/to/osmconf.ini input=name.pbf layer=lines output=osm_data

   Oracle Spatial
       Note  that  you have to set the environment-variables ORACLE_BASE, ORACLE_SID, ORACLE_HOME
       and TNS_ADMIN accordingly. input=OCI:username/password@database_instance output=grasslayer layer=roads_oci

   Multiple geometry columns
       This example shows how to work with data which contain multiple geometry per feature.  The
       number of geometry columns per feature can be checked by v.external together with -t flag.
       v.external -t input=20141130_ST_UKSH.xml.gz
       In   our   example   layer   "Okresy"   has   three   geometry   columns:  "DefinicniBod",
       "OriginalniHranice" and "GeneralizovanaHranice". By default reads data  from  all
       three  geometry  columns. The user can specify desired geometry column by geometry option,
       in this case the module will read geometry only from the specified geometry column. In the
       example   below,   the   output   vector   map   will   contain  only  geometry  saved  in
       "OriginalniHranice" geometry column. input=20141130_ST_UKSH.xml.gz layer=Okresy geometry=OriginalniHranice


       If a message like
       WARNING: Area size 1.3e-06, area not imported
       appears, the min_area may be adjusted to a smaller value so that all areas  are  imported.
       Otherwise  tiny areas are filtered out during import (useful to polish digitization errors
       or non-topological data).

       If a message like
       Try to import again, snapping with at least 1e-008: ’snap=1e-008’
       appears, then the map to be imported contains topological errors. The message  suggests  a
       value  for  the  snap  parameter  to  be  tried.  For  more details, see above in Topology


   SQL syntax errors
       Depending on the currently selected SQL driver, error messages such as follows may arise:
       DBMI-SQLite driver error:
       Error in sqlite3_prepare():
       near "ORDER": syntax error
       DBMI-DBF driver error:
       SQL parser error:
       syntax error, unexpected DESC, expecting NAME processing ’DESC
       This indicates that a column name in the input dataset corresponds to a reserved SQL  word
       (here:  ’ORDER’  and  ’DESC’ respectively). A different column name has to be used in this
       case. The columns parameter can be used to assign different column names  on  the  fly  in
       order to avoid using reserved SQL words.  For a list of SQL reserved words for SQLite (the
       default driver), see here.

   Projection errors
       Projection of dataset does not appear to match the current location.
       Here you need to create or use a location whose projection matches that of the vector data
       you  wish  to import. Try using location parameter to create a new location based upon the
       projection information in the file. If desired, you can  then  re-project  it  to  another
       location with v.proj.


           ·   OGR vector library

           ·   OGR vector library C API documentation


        db.connect, v.clean, v.extract,, v.edit, v.external, v.import,,, v.out.ogr

       GRASS GIS Wiki page: Import of Global datasets


       Original author: Radim Blazek, ITC-irst, Trento, Italy
       Location and spatial extent support by Markus Neteler and Paul Kelly
       Various improvements by Markus Metz
       Multiple geometry columns support by Martin Landa, OSGeoREL, Czech Technical University in
       Prague, Czech Republic

       Last changed: $Date: 2018-10-14 13:08:03 +0200 (Sun, 14 Oct 2018) $


       Available at: source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual