As both an SAP Partner and a Microsoft Partner specialising in Azure, we have delivered many SAP integrations using Azure Integration Services.

Breaking down this diagram, we can see that on the Azure cloud side there are:

• an Azure Logic App
• a custom Azure connector

And on the on-premise side we have:

• an Azure on-premise data gateway
• an ASP.NET Core API
• and, of course, the SAP HANA system

In this guide we’re going to cover the two main development processes required:

1. creating the custom Azure Logic Apps connector
2. creating the on-premise ASP.NET Core API

In this part you’ll see how straightforward it is to create a custom Logic Apps connector. This guide covers creating the custom connector resource, after which you’ll have to define its behaviour with an OpenAPI or Postman definition.

1. Choose “Create a resource” on the Azure services menu in the Azure portal.

2. In New, search for “logic apps custom connector”. Then select “Logic Apps Custom Connector”.

3. Select “Create” within the Logic Apps Custom Connector window.

4. Register your connector with the necessary details (see this example):

Now click on “Review + create”.

5. Review the details you entered in Create Logic Apps Custom Connector and finally select “Create”.

At this point the custom connector menu should open automatically. If not, open it directly from the relevant subscription and resource group. You’re now ready to define the connector’s behaviour with Postman or OpenAPI.

In this second part, you’ll learn how to develop the on-premise .NET Core application. We’re assuming you already have the .NET Core SDK installed on your machine.

1. Create a new console app with the commands below:

Shell (Windows)
cd %HOMEPATH%/HANAClientsTutorial
dotnet new console -o dotNET

Shell (Linux or Mac)
export HDBDOTNETCORE=/home/dan/sap/hdbclient/dotnetcore
cd $HOME/HANAClientsTutorial
dotnet new console -o dotNET

If using Linux or Mac, you should change the HDBDOTNETCORE variable to point to the location of the libadonetHDB.so or libadonetHDB.dylib file.

2. Open the dotNET.csproj file:

Shell (Windows)
cd dotNET
notepad dotNET.csproj

Shell (Linux or Mac)
cd dotNET
pico dotNET.csproj

Next, add the code below under the PropertyGroup section to indicate where to load the SAP HANA Client .NET Core driver from. Change the HintPath section with the details of where the dll is on your machine.

Shell (Microsoft Windows)
<ItemGroup>
<Reference Include="Sap.Data.Hana.Core.v2.1">
<HintPath>C:\SAP\hdbclient\dotnetcore\v2.1\Sap.Data.Hana.Core.v2.1.dll</HintPath>
</Reference>
</ItemGroup>

Shell (Linux or Mac)
<ItemGroup>
<Reference Include="Sap.Data.Hana.Core.v2.1"> <HintPath>/home/dan/sap/hdbclient/dotnetcore/v2.1/Sap.Data.Hana.Core.v2.1.dll</HintPath>
</Reference>
</ItemGroup>

When you’ve updated the dotNet.csproj file, save and close. The SAP HANA Client interface for .NET Core is compatible with version 2.1, and 3.x releases of .NET Core.

3. Use a code editor to edit the file Program.cs.

Shell (Windows)
notepad Program.cs

Shell (Linux or Mac)
pico Program.cs

4. Copy the code below and use it to replace everything in the Program.cs file:

C#
using System;
using Sap.Data.Hana;
namespace dotNETQuery
{
class Program
{
static void Main(string[] args)
{
try
{
// User1UserKey retrieved from hdbuserstore contains server:port, UID and PWD
// encrypt must be true when connecting to HANA Cloud
// If hdbuserstore is not used to retrieve the connnection information, the format would be
// "Server=10.7.168.11:39015;UID=User1;PWD=Password1;encrypt=true;sslValidateCertificate=false"
using (var conn = new HanaConnection("key=User1UserKey;encrypt=true;sslValidateCertificate=false"))
{
conn.Open();
Console.WriteLine("Connected");
var query = "SELECT TITLE, FIRSTNAME, NAME FROM HOTEL.CUSTOMER";
using (var cmd = new HanaCommand(query, conn))
using (var reader = cmd.ExecuteReader())
{
Console.WriteLine("Query result:");
// Print column names
var sbCol = new System.Text.StringBuilder();
for (var i = 0; i < reader.FieldCount; i++)
{
sbCol.Append(reader.GetName(i).PadRight(20));
}
Console.WriteLine(sbCol.ToString());
// Print rows
while (reader.Read())
{
var sbRow = new System.Text.StringBuilder();
for (var i = 0; i < reader.FieldCount; i++)
{
sbRow.Append(reader[i].ToString().PadRight(20));
}
Console.WriteLine(sbRow.ToString());
}
conn.Close();
}
}
}
catch (Exception ex)
{
Console.WriteLine("Error - " + ex.Message);
Console.WriteLine(ex.ToString());
}
}
}
}

Now save and close the Program.cs file. Take note of the fact that the address, port, UID and PWD will be retrieved from the hdbuserstore. This app uses some of the SAP HANA client .NET Core driver methods, such as HanaConnection. To learn more about this class, take a look at the Microsoft ADO.NET Connection Properties.