Update ddl.gsql

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demos/guru_scripts/docker/tutorial/4.x/script/ddl.gsql

@@ -1,9 +1,12 @@
+//create vertex types
 CREATE VERTEX Account ( name STRING PRIMARY KEY, isBlocked BOOL)
 CREATE VERTEX City ( name STRING PRIMARY KEY)
 CREATE VERTEX Phone (nmuber STRING PRIMARY KEY, isBlocked BOOL)
 
+//create edge types
 CREATE DIRECTED EDGE transfer (FROM Account, TO Account, DISCRIMINATOR(date DATETIME), amount UINT) WITH REVERSE_EDGE="transfer_reverse"
 CREATE UNDIRECTED EDGE hasPhone (FROM Account, TO Phone)
 CREATE DIRECTED EDGE isLocatedIn (FROM Account, TO City)
 
+//create graph; * means include all graph element types in the graph.
 CREATE GRAPH financialGraph (*)