Difference between revisions of "SpatiaLite"

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== Spatialite ==
 
== Spatialite ==
  
A {{Wikipedia|SQLite}} database with geospatial extensions, much list [[PostGIS]] is to {{Wikipedia|PostgreSQL}}.
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A {{Wikipedia|SQLite}} database with geospatial extensions, much list [[PostGIS]] is to {{Wikipedia|PostgreSQL}}. To export a vector map layer to a Spatialite database with v.out.ogr, use the SQLite [[OGR]] driver and set the SPATIALITE data creation option to "yes". Raster can be exported to a Spatialite database with r.out.gdal, using the Rasterlite format driver.
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==== Vector maps ====
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===== New database =====
  
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  v.out.ogr in=mymap output=mydbase.sqlite format=SQLite \
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    type=area dsco='SPATIALITE=yes' output_layer="mymap"
  
=== Export ===
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===== Existing spatialite database =====
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Note that you need to use --overwrite, otherwise v.out.ogr will complain that the output already exists. Using --overwrite should maintain the existing tables in the spatialite database. However, it is strongly suggested to run this on a copy of the database, or make sure you have a recent backup.
  
* ''fixme!'' this page is heavily under construction.
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  v.out.ogr -u in=mymap output=mydbase.sqlite format=SQLite \
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    type=area dsco='SPATIALITE=yes' output_layer="mymap" --overwrite
  
Use the SQLite [[OGR]] driver and set the SPATIALITE data creation option to "yes".
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====== Using QGIS (1) ======
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An alternate way is to load the layer in QGIS's GRASS toolbox, then right click on the layer name and select "Save As...".
  
v.out.ogr in=usgsgages dsn=usgsgages.sqlite format=SQLite type=point dsco='SPATIALITE=yes'  
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====== Using QGIS (2) ======
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Open the layer in QGIS using the browser panel. Next, open the spatialite database in the QGIS DB manager and use the 'import layer' option to import the grass vector layer you just opened in QGIS into the spatialite database.
  
fixme: I'm getting this error:
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==== Raster maps ====
ERROR 1: sqlite3_step() failed:
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Given an existing <var>mydbase.sqlite</var> file, and a Byte type rastermap <var>myraster</var>, invoking the following command will incorporate myraster to mydbase.sqlite as a LZW compressed PNG image :
  usgsgages.GEOMETRY violates Geometry constraint [geom-type or SRID not allowed] (19)
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  r.out.gdal input=myraster output="RASTERLITE:mydbase.sqlite,table=myraster" format=Rasterlite type=Byte createopt="DRIVER=PNG,COMPRESSION=LZW"
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For more information on the Rasterlite driver, have a look a [http://www.gdal.org/frmt_rasterlite.html gdal documentation].
  
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Note: the GDAL Rasterlite driver does not implement the SetProjection() method, thus srid value in the geometry_columns table will be set to -1 instead of a valid srid (12345 in the following example). You'll probably have to set it manually within the database:
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spatialite mydbase.sqlite
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.head on
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select srid from geometry_columns where f_table_name='myraster_metadata';
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update geometry_columns set srid=12345 where f_table_name='myraster_metadata';
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.exit
  
An alternate way is to load the layer in QGIS's GRASS toolbox, then right click on the layer name and select "Save As...".
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[[Category:FAQ]]

Latest revision as of 09:55, 2 February 2017

Spatialite

A SQLite database with geospatial extensions, much list PostGIS is to PostgreSQL. To export a vector map layer to a Spatialite database with v.out.ogr, use the SQLite OGR driver and set the SPATIALITE data creation option to "yes". Raster can be exported to a Spatialite database with r.out.gdal, using the Rasterlite format driver.

Vector maps

New database
 v.out.ogr in=mymap output=mydbase.sqlite format=SQLite \
   type=area dsco='SPATIALITE=yes' output_layer="mymap"
Existing spatialite database

Note that you need to use --overwrite, otherwise v.out.ogr will complain that the output already exists. Using --overwrite should maintain the existing tables in the spatialite database. However, it is strongly suggested to run this on a copy of the database, or make sure you have a recent backup.

 v.out.ogr -u in=mymap output=mydbase.sqlite format=SQLite \
   type=area dsco='SPATIALITE=yes' output_layer="mymap" --overwrite
Using QGIS (1)

An alternate way is to load the layer in QGIS's GRASS toolbox, then right click on the layer name and select "Save As...".

Using QGIS (2)

Open the layer in QGIS using the browser panel. Next, open the spatialite database in the QGIS DB manager and use the 'import layer' option to import the grass vector layer you just opened in QGIS into the spatialite database.

Raster maps

Given an existing mydbase.sqlite file, and a Byte type rastermap myraster, invoking the following command will incorporate myraster to mydbase.sqlite as a LZW compressed PNG image :

 r.out.gdal input=myraster output="RASTERLITE:mydbase.sqlite,table=myraster" format=Rasterlite type=Byte createopt="DRIVER=PNG,COMPRESSION=LZW"

For more information on the Rasterlite driver, have a look a gdal documentation.

Note: the GDAL Rasterlite driver does not implement the SetProjection() method, thus srid value in the geometry_columns table will be set to -1 instead of a valid srid (12345 in the following example). You'll probably have to set it manually within the database:

spatialite mydbase.sqlite
.head on
select srid from geometry_columns where f_table_name='myraster_metadata';
update geometry_columns set srid=12345 where f_table_name='myraster_metadata';
.exit