Improve SQLite3 example (#3083)

Co-authored-by: Riccardo Magliocchetti <[email protected]>

Author: Kludex

instrumentation/opentelemetry-instrumentation-sqlite3/src/opentelemetry/instrumentation/sqlite3/__init__.py

@@ -29,8 +29,9 @@
 
     SQLite3Instrumentor().instrument()
 
-    cnx = sqlite3.connect('example.db')
+    cnx = sqlite3.connect(':memory:')
     cursor = cnx.cursor()
+    cursor.execute("CREATE TABLE test (testField INTEGER)")
     cursor.execute("INSERT INTO test (testField) VALUES (123)")
     cursor.close()
     cnx.close()