arangosh> a1 = db.example.insert({"a" : 1}); { "_id" : "example/74301", "_key" : "74301", "_rev" : "_ZXF6dQu--A" } arangosh> a2 = db.example.update(a1, {"b" : 2, "c" : 3}); { "_id" : "example/74301", "_key" : "74301", "_rev" : "_ZXF6dQy--_", "_oldRev" : "_ZXF6dQu--A" } arangosh> a3 = db.example.update(a1, {"d" : 4}); [ArangoError 1200: precondition failed] arangosh> a4 = db.example.update(a2, {"e" : 5, "f" : 6 }); { "_id" : "example/74301", "_key" : "74301", "_rev" : "_ZXF6dQy--B", "_oldRev" : "_ZXF6dQy--_" } arangosh> db.example.document(a4); { "_key" : "74301", "_id" : "example/74301", "_rev" : "_ZXF6dQy--B", "a" : 1, "c" : 3, "b" : 2, "f" : 6, "e" : 5 } arangosh> a5 = db.example.update(a4, {"a" : 1, c : 9, e : 42 }); { "_id" : "example/74301", "_key" : "74301", "_rev" : "_ZXF6dQ2--_", "_oldRev" : "_ZXF6dQy--B" } arangosh> db.example.document(a5); { "_key" : "74301", "_id" : "example/74301", "_rev" : "_ZXF6dQ2--_", "a" : 1, "c" : 9, "b" : 2, "f" : 6, "e" : 42 }