add export (to SQLite or geopackage) function to the geoslurper client

clitools/geoslurper.py

@@ -178,7 +178,7 @@ def main(argv):
         sys.exit(0)
 
 
-    if not (args.pull or args.register or args.purge_cache or args.purge_data or args.purge_entry):
+    if not (args.pull or args.register or args.purge_cache or args.purge_data or args.purge_entry or args.export):
         sys.exit(0)
 
     if args.pull:
@@ -226,6 +226,10 @@ def main(argv):
                 ds.register(**regopts)
             except KeyboardInterrupt:
                 ds.halt()
+
+        if args.export:
+            ds.export(args.export)
+
         #We need to explicitly delete the dataset instance or else the database QueuePool gets exhausted 
         del ds
 
@@ -329,6 +333,8 @@ def addCommandLineArgs():
 
         parser.add_argument("--register", metavar="JSON",action=JsonParseAction, nargs="?",const=False, default=False,
                             help="Register data in the database (possibly pass on options as a JSON dict)")
+        parser.add_argument("--export", metavar="OUTPUTFILE",type=str, nargs="?",const="auto", default=False,
+                            help="Export the selected tables in a SQLITE or geopackage file. The type of output is determined from the OUTPUTFILE extension (.sql or .gpkg). When no OUTPUTFILE is provided an SQLITE or gpkg file is dumped in the current directory (depending on whether thee table has a geometry columns.")
 
         # parser.add_argument("--update", metavar="JSON", action=JsonParseAction, nargs="?",const=False,default=False,
                             # help="Implies both --pull and --register, but applies only to the updated data (accepts JSON options)")

geoslurp/dataset/dataSetBase.py

@@ -29,7 +29,7 @@
 from sqlalchemy import and_
 from geoslurp.db.settings import getCreateDir
 from geoslurp.db import tableMapFactory
-
+from geoslurp.db.exporter import exportQuery
 
 def rmfilterdir(ddir,filter='*'):
     """Remove directories and files based on a certain regex filter"""
@@ -337,14 +337,26 @@ def migrate(self,version):
             raise RuntimeError("No migration implemented")
         if version > self.version:
             raise RuntimeError("Registered database has a higher version number than supported")
+
+    def export(self,outputfile):
+        """Export the table to a different format"""
+        qry=f"SELECT * FROM {self.scheme}.{self.name};"
+        qryres=self.db.dbeng.execute(qry)
+        layer=f"{self.name}"
+        if outputfile == "auto":
+            #create a name based on the current scheme and table name
+            if "geom" in qryres.keys():
+                outputfile=f"{self.scheme}_{self.name}.gpkg"
+            else:
+                outputfile=f"{self.scheme}_{self.name}.sql"
+        if outputfile.endswith(".gpkg"):
+            driver="GPKG"
+        elif outputfile.endswith(".sql"):
+            driver="SQLITE"
+        else:
+            raise RuntimeError("in Export: Unknown outputfile selected")
 
-
-    # def loadTable(self):
-        # """Reflects a dataset table from the database"""
-        # if self.table:
-            # slurplogger().warning("Reflecting and overwriting existing database table with data from server")
+        slurplogger().info(f"Exporting table to {outputfile}")
+        exportQuery(qryres,outputfile,layer=layer,driver=driver)
 
 
-        # if custumcolumns in self._dbinvent.data:
-            # #override columns with customn types
-            # cols=

geoslurp/db/exporter.py

@@ -19,7 +19,7 @@
 import geopandas as gpd
 import pandas as pd
 from geoslurp.tools.shapelytools import shpextract
-from geoslurp.db.settings import MirrorMap
+# from geoslurp.db.settings import MirrorMap
 import re
 import tarfile
 from sqlalchemy import create_engine