wiki:Grass7/VectorLib/OGRInterface

Version 21 (modified by martinl, 13 years ago) ( diff )

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OGR interface in GRASS 7

Direct OGR read access

Capability to read OGR layers directly without linking them via v.external. Example:

v.info map=~/shapefiles/@OGR layer=busstopsall
v.extract input=PG:dbname=nc_spm_08@OGR layer=busstopsall where="STREET_1 = 'William Moore Dr.'" output=b1

List of modules which supports direct OGR read access ((*) indicates work in progress):

Direct OGR write access

Capability to write OGR layers directly without need to store data in the native GRASS vector format and then exporting data using v.out.ogr.

Testcase:

  • location: nc_spm_08
  • Shapefile directory: ~/ncshape
  • PostGIS database: pgis_nc

Scenario 1

Use parameters output for output OGR datasource and olayer for OGR layer. Example:

# input: GRASS data
# output: PostGIS database
v.extract map=obce where="NAZEV = Solany" output=PG:dbname=gisdb@OGR olayer=obce

# input: PostGIS layer, ESRI Shapefile
# output: PostGIS database
v.select ainput=PG:dbname=gisdb@OGR alayer=zeleznice \
 binput=shps@OGR blayer=obce operator=intersects \
 output=PG:dbname=gisdb@OGR olayer=obce_zelez

Status: not planned to be implemented

Scenario 2

Use v.external.out

# input: GRASS data
# output: PostGIS database
v.external.out dsn=PG:dbname=pgis_nc format=PostgreSQL
v.extract input=bridges where="BRIDGE_NUM=417" output=bridges_417

# input: PostGIS layer, ESRI Shapefile
# output: PostGIS database
v.select ainput=PG:dbname=gisdb@OGR alayer=zeleznice \
 binput=shps@OGR blayer=obce operator=intersects \
 output=obce_zelez

Status: implemented grass/trunk/vector/v.external.out

Tasks

  • Attribute table (write) access for OGR-linked vectors (direct or linked by v.external)

Changes in vector library

Changes in modules

List of modules which supports direct OGR write access ((*) indicates work in progress):

  • v.edit
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