Alter VersionChecker.getPostGISVersion to not use psql process

[palmerj]

In many cases windows users don't have the psql process available. In this case the version checking will fail. However the GDAL/OGR library has PG LIB support as part of the postgresql driver.

A better way might just be to use GDAL to get the version. i.e

from osgeo import gdal
from osgeo import ogr

driver = ogr.GetDriverByName("PostgreSQL")

pg_ds = None
postgis_version = None
version = None

try:
    # gdal.PushErrorHandler( 'CPLQuietErrorHandler' )
    pg_ds = ogr.Open( 'PG:dbname=mydb' )
    # gdal.PopErrorHandler()
except:
    pass
    # do some exception logging

ver_lyr = pg_ds.ExecuteSQL('SELECT version()')
feat = ver_lyr.GetNextFeature()
version_str = feat.GetFieldAsString('version')

version = float(version_str[11:14])

ver_lyr = pg_ds.ExecuteSQL('SELECT postgis_version()')
pg_has_postgis = ver_lyr is not None
if pg_has_postgis:
    feat = ver_lyr.GetNextFeature()
    version_str = feat.GetFieldAsString('postgis_version')
    postgis_version = float(version_str[0:3])
pg_ds.ReleaseResultSet(ver_lyr)

print "PostgreSQL Version: " + str(version)
if pg_has_postgis:
    print "PostGIS Version: " + str(postgis_version)
else:
    print "PostGIS Is not available"

[josephramsay]

Thanks. I thought I had this covered but was just for GDAL. Delayed version checking till DS initialisation and pushed checking into subclasses. e.g.

    def versionCheck(self):
        '''SpatiaLite/SQLite version checker'''
        from VersionChecker import VersionChecker,UnsupportedVersionException

        slv_cmd = 'file '+str(self._commonURI(None))

        slv_ver = VersionChecker.getVersionFromShell(slv_cmd,'SQLite (\d+.\w+) database')

        if VersionChecker.compareVersions(VersionChecker.SpatiaLite_MIN, slv_ver if slv_ver is not None else VersionChecker.SpatiaLite_MIN):
            raise UnsupportedVersionException('SpatiaLite version '+str(slv_ver)+' does not meet required minumum '+str(VersionChecker.SpatiaLite_MIN))

        return True

[palmerj]

Great - Looks good.

Any reason to only support PostgreSQL 9.0+? I would have thought 8.4+ would be easy to support. Which specific 9.0 features are you using?

BTW. 8.4 is still a fully supported version for the PostgreSQL community. PostGIS 2.0 also works with 8.4+. PostGIS 2.1 will however require 9.0.

[josephramsay]

Thanks.

No good reason, was just setting the minimum back to a last major release before a confirmed working version. Its 8.4 now

[palmerj]

Cool.