Cosmos DB Connector - Using T-SQL / Linked Server

T-SQL is a programming language used for managing and querying data in Microsoft SQL Server databases. We provides tools for data integration, automation, and connectivity.

If you want to use T-SQL with ZappySys, you can use our Connector, which allows you to connect to SQL Server databases and execute T-SQL queries from Cosmos DB.

Create Data Source in ZappySys Data Gateway based on API Driver

Download and install ZappySys ODBC PowerPack.
Search for gateway in start menu and Open ZappySys Data Gateway:
Go to Users Tab to add our first Gateway user. Click Add; we will give it a name tdsuser and enter password you like to give. Check Admin option and click OK to save. We will use these details later when we create linked server:
Now we are ready to add a data source. Click Add, give data source a name (Copy this name somewhere, we will need it later) and then select Native - ZappySys API Driver. Finally, click OK. And it will create the Data Set for it and open the ZS driver UI.

CosmosDbDSN
When the Configuration window appears give your data source a name if you haven't done that already, then select "Cosmos DB" from the list of Popular Connectors. If "Cosmos DB" is not present in the list, then click "Search Online" and download it. Then set the path to the location where you downloaded it. Finally, click Continue >> to proceed with configuring the DSN:

CosmosDbDSN

Cosmos DB

Now it's time to configure the Connection Manager. Select Authentication Type, e.g. Token Authentication. Then select API Base URL (in most cases, the default one is the right one). More info is available in the Authentication section.

ApiKey [Http]

Steps to get Cosmos DB Credentials : ApiKey [Http]
Connecting to your Azure Cosmos DB data requires you to authenticate your REST API access. Follow the instructions below:

Go to your Azure portal homepage: https://portal.azure.com/
In the search bar at the top of the homepage, enter Azure Cosmos DB. In the dropdown that appears, select Azure Cosmos DB.
Click on the name of the database account you want to connect to. (Also copy and paste the name of the database account for later use.)
On the next page where you can see all of the database account information, look along the left side and select Keys.
On the Keys page, you will have two tabs: Read-write Keys and Read-only Keys. If you are going to write data to your database, you need to remain on the Read-write Keys tab. If you are only going to read data from your database, you should select the Read-only Keys tab.
On the Keys page, copy the PRIMARY KEY value and paste it somewhere for later use. (The SECONDARY KEY value may also be copied and pasted instead of PRIMARY KEY.)
Back at the connector screen, enter the primary or secondary key you recorded in step 6 into the Primary or Secondary Key field.
Enter the database account you recorded in step 3 into the Database Account field.
Enter or select the default database you want to connect to using the Defualt Database field.
Enter or select the default table (i.e. container/collection) you want to connect to using the Default Table (Container/Collection) field.
Select the Test Connection button at the bottom of the window to verify proper connectivity with your Azure Devops account.
If the connection test succeeds, select OK.

Fill in all required parameters and set optional parameters if needed:

CosmosDbDSN

Cosmos DB

ApiKey [Http]

https://[$Account$].documents.azure.com

Required Parameters
Primary or Secondary Key	Fill in the parameter...
Account Name (Case-Sensitive)	Fill in the parameter...
Database Name (keep blank to use default) Case-Sensitive	Fill in the parameter...
API Version	Fill in the parameter...
Optional Parameters
Default Table (needed to invoke #DirectSQL)	Fill in the parameter...

Once the data source has been configured, you can preview data. Select the Preview tab and use settings similar to the following to preview data:
Click OK to finish creating the data source.

Read data in SQL Server from the ZappySys Data Gateway

To read the data in SQL Server the first thing you have to do is create a Linked Server. Go to SQL Server Management Studio and configure it in a similar way:
Then click on Security option and configure username we created in ZappySys Data Gateway in one of the previous steps:
Optional: Under the Server Options, Enable RPC and RPC Out and Disable Promotion of Distributed Transactions(MSDTC).

You need to enable RPC Out if you plan to use EXEC(...) AT [MY_LINKED_SERVER_NAME] rather than OPENQUERY.
If don't enabled it, you will encounter the Server 'MY_LINKED_SERVER_NAME' is not configured for RPC error.

Query Example:
```
EXEC('Select * from Products') AT [MY_LINKED_SERVER_NAME]
```
If you plan to use 'INSERT INTO...EXEC(....) AT [MY_LINKED_SERVER_NAME]' in that case you need to Disable Promotion of Distributed Transactions(MSDTC).
If don't disabled it, you will encounter the The operation could not be performed because OLE DB provider "SQLNCLI11" for linked server "MY_LINKED_SERVER_NAME" was unable to begin a distributed transaction. error.

Query Example:
```
Insert Into dbo.Products
 EXEC('Select * from Products') AT [MY_LINKED_SERVER_NAME]
```
Finally, open a new query and execute a query we saved in one of the previous steps:
```
SELECT * FROM OPENQUERY([MY_LINKED_SERVER_NAME], 'SELECT * FROM Products');
```

Create Linked Server using Code

In previous section you saw how to create a Linked Server from UI. You can do similar action by code too (see below). Run below script after changing necessary parameters. Assuming your Data Source name on ZappySys Data Gateway UI is 'CosmosDbDSN'


    USE [master]
    GO
    --///////////////////////////////////////////////////////////////////////////////////////
    --Run below code in SSMS to create Linked Server and use ZappySys Drivers in SQL Server
    --///////////////////////////////////////////////////////////////////////////////////////

    //Replace YOUR_GATEWAY_USER, YOUR_GATEWAY_PASSWORD
    //Replace localhost with IP/Machine name if ZappySys Gateway Running on different machine other than SQL Server
    //Replace Port 5000 if you configured gateway on a different port


    --1. Configure your gateway service as per this article https://zappysys.com/links?id=10036

    --2. Make sure you have SQL Server Installed. You can download FREE SQL Server Express Edition from here if you dont want to buy Paid version https://www.microsoft.com/en-us/sql-server/sql-server-editions-express

    --Uncomment below if you like to drop linked server if it already exists
    --EXEC master.dbo.sp_dropserver @server=N'LS_CosmosDbDSN', @droplogins='droplogins'

    --3. Create new linked server

    EXEC master.dbo.sp_addlinkedserver
      @server = N'LS_CosmosDbDSN'  --Linked server name (this will be used in OPENQUERY sql
    , @srvproduct=N''
    ---- For MSSQL 2012,2014,2016 and 2019 use below (SQL Server Native Client 11.0)---
    , @provider=N'SQLNCLI11'
    ---- For MSSQL 2022 or higher use below (Microsoft OLE DB Driver for SQL Server)---
    --, @provider=N'MSOLEDBSQL'
    , @datasrc=N'localhost,5000' --//Machine / Port where Gateway service is running
    , @provstr=N'Network Library=DBMSSOCN;'
    , @catalog=N'CosmosDbDSN' --Data source name you gave on Gateway service settings

    --4. Attach gateway login with linked server

    EXEC master.dbo.sp_addlinkedsrvlogin
    @rmtsrvname=N'LS_CosmosDbDSN'  --linked server name
    , @useself=N'False'
    , @locallogin=NULL
    , @rmtuser=N'YOUR_GATEWAY_USER' --enter your Gateway user name
    , @rmtpassword='YOUR_GATEWAY_PASSWORD'  --enter your Gateway user's password
    GO

    --5. Enable RPC OUT (This is Optional - Only needed if you plan to use EXEC(...) AT YourLinkedServerName rather than OPENQUERY
    EXEC sp_serveroption 'LS_CosmosDbDSN', 'rpc', true;
    EXEC sp_serveroption 'LS_CosmosDbDSN', 'rpc out', true;

    --Disable MSDTC - Below needed to support INSERT INTO from EXEC AT statement
    EXEC sp_serveroption 'LS_CosmosDbDSN', 'remote proc transaction promotion', false;

    --Increase query timeout if query is going to take longer than 10 mins (Default timeout is 600 seconds)
    --EXEC sp_serveroption 'LS_CosmosDbDSN', 'query timeout', 1200;
    GO