Develop Reference

"Write" Transactions don't work when using C#/Node.js with Amazon Neptune

I am able to connect to Neptune and was able to add some data to it with no issues. However, when I tried the code at https://tinkerpop.apache.org/docs/current/reference/#gremlin-dotnet-transactions it doesn't seem to work. I receive following error:
"Received data deserialized into null object message. Cannot operate on it."
I even jumped to a JS sample (https://tinkerpop.apache.org/docs/current/reference/#gremlin-javascript-transactions) and tried again. It doesn't work either.
What am I missing?

At the time of this writing, Amazon Neptune only has support for TinkerPop version 3.4.11. The "traversal transactions" semantics using tx(), that you are referencing, is new as of 3.5.2 that was released by Apache TinkerPop in mid January 2022.
Transactions are typically only required when you need to submit multiple queries but have all of the queries bounded within a single commit, or with rollback if one of the queries were to fail. If you don't need this, then each Gremlin query sent to Neptune behaves as a single transaction.
If you do need transaction-like behavior in 3.4.11, here's a link to the documentation on how to do that in Neptune using Gremlin sessions: https://docs.aws.amazon.com/neptune/latest/userguide/access-graph-gremlin-sessions.html
If you don't need transactions, then here are examples of interacting with Neptune by submitting individual queries:
(.NET) https://docs.aws.amazon.com/neptune/latest/userguide/access-graph-gremlin-dotnet.html
(JS) https://docs.aws.amazon.com/neptune/latest/userguide/access-graph-gremlin-node-js.html

Adding and reading from from azure mobile service

I created a mobile service app using azure connected it to SQL DB that has this table
now trying to insert and retrieve data in my Windows Universal App gives me this error:
I tried many things one of them was this code:
HighScore item = new HighScore
{
SCORE = "100",
playerName = "Mark"
};
await App.MobileService.GetTable<HighScore>().InsertAsync(item);
tried also to get the table bu name but no luck, now what is weird for me is that this same code works perfectly on the TodoItem Table but not on other tables.
Thanks in advance

The MobileServiceInvalidOperationException is a wrapper exception. The actual exception is in an InnerException inside that object. Based on the error message, your insert is not working.
You have provided no information on how you constructed the backend. Don't forget that you need to create the table in the SQL database and you need to create an appropriate controller for exposing the database table to your mobile client.
You have not provided any information on what the entity on your mobile client looks like. It needs to match the information you want to send to the backend.
Finally, take a look at my book - http://aka.ms/zumobook - Chapter 3 of the book goes into great detail on the data protocol.

SQL Dependency not working

I am trying to use SQLDependency in my windows application and have followed the steps defined How can I notify my program when the database has been updated? and http://dotnet.dzone.com/articles/c-sqldependency-monitoring
I have enabled Service Broker, set up the queue, created a servie on queue:
ALTER DATABASE [Company] SET ENABLE_BROKER;
CREATE QUEUE ContactChangeMessages;
CREATE SERVICE ContactChangeNotifications
ON QUEUE ContactChangeMessages
([http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification]);
The next step is to let the SQL user subscribe to the query notifications. I understand I can provide the login user, which is sa (verified using the query SELECT * FROM sys.server_principals):
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO sa;
But I am getting "Cannot find the user 'sa', because it does not exist or you do not have permission."
I have used other users like sysadmin too to grant the permission but every time I was getting the same error. Then I read # http://ask.sqlservercentral.com/questions/7803/msg-15151-level-16-state-1-line-1-cannot-find-the.html) that the permission needs to be provided to a user and not to a login which I did. So now I have provided the permission to 'public' and 'guest' and the sql query executes successfully and not to dbo ("Cannot grant, deny, or revoke permissions to sa, dbo, entity owner, information_schema, sys, or yourself.")
The application code in c# is not too complicated and I have followed the links provided at the beginning so not putting the code here (surely I changed the queue name etc. in line with the sql commands above). But the SQlDependency does not seem to be working when I change the table records (insert/delete).
Where am I going wrong? Is there any step which I am missing

Try:
use [master]
go
alter authorization on database::[YourDatabaseName] to [sa]
go

C# creating a database programmatically with SMO

I am trying to create a database, but once created, I cannot connect to it.
The server is Microsoft SQL Server 2008 and using .Net 4.5. We're creating the database with SMO, but we're usually using Dapper to connect and query the database.
This is the code I have so far, which works :
System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(connectionString);
Microsoft.SqlServer.Management.Smo.Server srv = new Microsoft.SqlServer.Management.Smo.Server(new Microsoft.SqlServer.Management.Common.ServerConnection(con));
var database = new Microsoft.SqlServer.Management.Smo.Database(srv, dbName);
database.Create(false);
database.Roles["db_datareader"].AddMember(???);
database.Roles["db_datawriter"].AddMember(???);
database.Roles["db_backupoperator"].AddMember(???);
srv.Refresh();
Noce the ??? ? I have tried
System.Environment.UserDomainName + "\\" + System.Environment.UserName
and
System.Environment.UserName
but it fails (update) with the error Add member failed for DatabaseRole 'db_datareader'. with both values.
The problem is that when I create the database, I cannot coonect to it for some reason (using Dapper), from the same program. (update) I get the error message : Cannot open database \"<database_name>\" requested by the login. The login failed.\r\nLogin failed for user '<domain>\\<username>' (where <database_name> is the database name, <domain> my logon domain, and <username> my Windows logon).
Am I missing something? Am I doing th right thing? I've tried searching the web, but it seems no one creates database this way. The methods are there, it should work, no?
** Update **
If I comment the database.Roles["..."].AddMember(...) lines, and I add a break point at srv.Refresh(), resuming the program from there solves everything.
Why a break point solves everything? I can't just break the program in production... nor break the program when creating the database everytime.

It sounds like the Dapper connection issue is a problem with SQL Server doing some of the SMO operations asynchronously. In all likelihood, the new Database is not ready for other users/connections immediately, but requires some small time for SQL Server to prepare it. In "human-time" (in SSMS, or a Breakpoint) this isn't noticeable, but "program-time" it too fast, so you probably need to give it a pause.
This may also be the problem with the Role's AddMember, but there a a number of things that could be wrong here, and we do not have enough information to tell. (specifically, does AddMember work later on? and are the strings being passed correct or not?)

This is happening because you've created the user, but no login for that user. Though I don't know the exact syntax, you're going to have to create a Login. You'll want to set its LoginType to LoginType.WindowsUser. Further, you'll likely need to set the WindowsLoginAccessType to WindowsLoginAccessType.Grant and you'll need to set the Credential by building one, probably a NetworkCredential with the user name you want.
To put a visual on this, the Login is under the Security node for the Server in Management Studio whereas the User is under the Security node for the Database. Both need to exist for access to the SQL Server.

Trouble with duplicating a transaction's functionality

I'm updating a current program that is working and in use on a Live environment, it saves Customers and Orders then exports them to an old database as well. All of the Reporting is still done in the old system while the reporting system in the new system is in development, which is why these all need to be exported.
This program has a built-in C# TransactionManager that is used to group multiple calls from C# to SQL within one transaction. Whenever I try to duplicate this I get errors and can't get it working.
Here's the code that is in place, working:
using (ITransactionInfo trx = this.TransactionManager.BeginTransaction())
{
//
// Update the customer. If the customer doesn't exist, then create a new one.
//
this.SaveCustomer(Order);
//
// Save the Order.
//
this.Store.SaveCorporateOrder(Order, ServiceContext.UserId);
//
// Save the Order notes and the customer notes.
//
this.NotesService.AppendNotes(NoteObjectTypes.CorporateOrder, Order.Id, Order.OrderNotes);
this.NotesService.AppendNotes(NoteObjectTypes.Customer, Order.Customer.Id, Order.CustomerNotes);
//
// Export the Order if it's new.
//
this.ExportOrder(Order, lastSavedVersion);
//
// Commit the transaction.
//
trx.Commit();
}
All of these functions just format the data and send parameters to Stored Procedures in the DB that perform the Select / Insert / Update operations on the DB.
The SaveCustomer stored procedure saves the customer to the new database.
The SaveCorporateOrder stored procedure gets information that was writen by the Save Customer stored procedure and uses it to save the Order to the new database.
The ExportOrder stored procedure gets information that was written by both of the previous ones and exports the Order to the old database.
Each of these stored procedures contain code that starts a new transaction if ##TRANCOUNT == 0 and have a commit statement at the end. It appears that none of these are being used because of the transaction in C#, but there is no code that passes transaction information or connection information to the stored procedures that I can see. This is working and in use on a SQL 2005 server.
When I try to build this and use it on my development environment that uses SQL 2008R2, I get errors like
"Uncommittable transaction is detected at the end of the batch"
and
"The server failed to resume the transaction"
It appears that each one is starting it's own transaction and is unable to read the data from the previous, uncommitted transaction instead of seeing that it is in the same transaction. I don't know if the different SQL version could be causing this to work differently or not, but the exact same code works in the Live install but not on my Dev environment.
Any ideas, or even direction where to look next would be wonderfull!
Thanks!
-Jacob

I think that the problem is because transaction fails and is not rejected. You don't have rollback call for the situation when any of SQL queries fail. Have you checked those queries?