How does thingworx manage the transaction of Database Things ?

Hi, 

I thought thingworx manage the transaction automatically for Database things and for each service will start a new or existing transaction.   However,  it doesn't behavior as my assumption.   

For  example: 

TestDbTransA and TestDbTransB are Database things and the service AddOne & AddThree are SQL command services.   I expect the service AddOne doesn't take effect as the exception occurs and the transaction should get rollback,   however ,  AddOne service still insert record into the database.  

So how does thingworx manager the transaction of database things ? 

(function(){
var result = Things["TestDbTransA"].AddOne({
field: "1111" /* STRING */,
name: "1111" /* STRING */,
id: "1111" /* STRING */
});

if(true){
 throw new Error("Error occurs, AddOne is supposed to be rollback");
}

var result2 = Things["TestDbTransB"].AddThree({
field: "3333" /* STRING */,
name: "3333" /* STRING */,
id: "3333" /* STRING */
}); 
})();

 Regards,

Sean