added tests for BerkeleyDB store

1 files changed, 18 insertions, 3 deletions

diff --git a/examples/berkeleydb_example.py b/examples/berkeleydb_example.py
index eec5464e..abeef3ba 100644
--- a/examples/berkeleydb_example.py
+++ b/examples/berkeleydb_example.py
@@ -1,6 +1,13 @@
 """
-A simple example showing how to use a BerkeleyDB store to do on-disk
-persistence.
+A simple example showing how to use a BerkeleyDB store to do on-disk persistence:
+
+* creating a ConjunctiveGraph using the BerkeleyDB Store
+* adding triples to it
+* counting them
+* closing the store, emptying the graph
+* re-opening the store using the same DB files
+* getting the same count of triples as before
+
 """
 
 from rdflib import ConjunctiveGraph, Namespace, Literal
@@ -8,21 +15,27 @@ from rdflib.store import NO_STORE, VALID_STORE
 
 from tempfile import mktemp
 
+
 if __name__ == "__main__":
     path = mktemp()
 
-    # Open previously created store, or create it if it doesn't exist yet
+    # Declare we are using a BerkeleyDB Store
     graph = ConjunctiveGraph("BerkeleyDB")
 
+    # Open previously created store, or create it if it doesn't exist yet
+    # (always doesn't exist in this example as using temp file location)
     rt = graph.open(path, create=False)
 
     if rt == NO_STORE:
         # There is no underlying BerkeleyDB infrastructure, so create it
+        print("Creating new DB")
         graph.open(path, create=True)
     else:
+        print("Using existing DB")
         assert rt == VALID_STORE, "The underlying store is corrupt"
 
     print("Triples in graph before add:", len(graph))
+    print("(will always be 0 when using temp file for DB)")
 
     # Now we'll add some triples to the graph & commit the changes
     EG = Namespace("http://example.net/test/")
@@ -34,6 +47,7 @@ if __name__ == "__main__":
     graph.commit()
 
     print("Triples in graph after add:", len(graph))
+    print("(should be 2)")
 
     # display the graph in Turtle
     print(graph.serialize())
@@ -49,6 +63,7 @@ if __name__ == "__main__":
     graph.open(path, create=False)
 
     print("Triples still in graph:", len(graph))
+    print("(should still be 2)")
 
     graph.close()