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Hi All,
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<div class="">Is it possible to write a layer w/ a custom CRS to a spatialite database with pyQgis? Here’s what I’ve tried:</div>
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<div class="">1) create an empty spatialite database</div>
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<div class="">2) add custom QGIS crs to spatial_ref_sys table in spatialite database using the following sql command:</div>
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<div class="">sql = """INSERT INTO spatial_ref_sys(srid, auth_name, auth_srid, ref_sys_name, proj4text, srtext) VALUES({0}, '', '', '{3}', '{1}', '{2}')""".format(layer.crs().authid()[5:], layer.crs().toProj4(), layer.crs().toWkt(), layer.crs().description())</div>
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<div class="">3) write layer to database using the following:</div>
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<div style="margin: 0px;" class=""><!--StartFragment-->def loadVectorsIntoDB(layers, dbase):</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>#database import options</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>options = {}</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>options['overwrite'] = True</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>options['forceSinglePartGeometryType'] = True</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>uri = QgsDataSourceURI()</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>uri.setDatabase(dbase)</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>for layer in layers:</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>uri.setDataSource('',layer.name(),'the_geom')</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>ret, errMsg = QgsVectorLayerImport.importLayer(layer, uri.uri(), 'spatialite', layer.crs(), False, False, options)</div>
<div style="margin: 0px;" class=""><span class="Apple-tab-span" style="white-space:pre"></span>del uri<!--EndFragment--></div>
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<div style="margin: 0px;" class="">The layer will be written to the database, but it is imported with an srid of 0 which is an Undefined - Geographic Long/Lat coordinate system, not the custom CRS.</div>
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<div style="margin: 0px;" class="">I have also tried to write a layer using DB manager instead of step 3 and got the same result. Is it possible to add the CRS to the spatial_ref_sys table in such a way it will match the layer.crs() argument in the QgsVectorLayerImport.importLayer()
function?</div>
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<div style="margin: 0px;" class="">Any hints would be great!</div>
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<div class="">Thanks,</div>
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Mitch</div>
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Mitchell Weier, P.E.<br class="">
Water Resource Engineer<br class="">
North Dakota State Water Commission<br class="">
900 E Boulevard Avenue, Dept.770<br class="">
Bismarck, ND 58505-0850<br class="">
(701) 328 1402 phone<br class="">
(701) 328 3696 fax<br class="">
<a href="mailto:mweier@nd.gov" class="">mweier@nd.gov</a></div>
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