Ready to get started?

Learn more about the CData ADO.NET Provider for HPCC or download a free trial:

Download Now

LINQ to HPCC Systems Data

LINQ provides general-purpose query facilities in .NET Framework 3.0 and above and provides one easy way to programmatically access data through from CData ADO.NET Data Providers. This example uses LINQ to access information from the HPCC Systems Data Provider.

This article demonstrates how to use LINQ to access HPCC Systems tables through the CData ADO.NET Data Provider for HPCC Systems. To do this you will LINQ to Entity Framework, which is used to generate the connection and can be used with any CData ADO.NET Data Providers to access data via LINQ.

See the help documentation for a guide to setting up an EF 6 project to use the provider.

  1. In a new project in Visual Studio, right-click on the project and choose to add a new item. Add an ADO.NET Entity Data Model.
  2. Choose EF Designer from Database and click Next.
  3. Add a new Data Connection, and change your data source type to "CData HPCC Systems Data Source".
  4. Enter your data source connection information.

    To connect, set the following connection properties: Set URL to the machine name or IP address of the server and the port the server is running on, for example, https://server:port. The User and Password are required to authenticate to the HPCC Systems cluster specified in the URL. Note that LDAP authentication is not currently supported by our ODBC driver.

    Set Version to the WsSQL Web server version. Note that if you have not already done so, you will need to install the WsSQL service on the HPCC Systems server. The WsSQL Web service is used to interact with the underlying HPCC Systems platform.

    Set Cluster to the target cluster.

    Below is a typical connection string:

    URL=http://127.0.0.1:8510;User=test;password=xA123456;Version=1;Cluster=hthor;
  5. If saving your entity connection to App.Config, set an entity name. In this example we are setting HPCCEntities as our entity connection in App.Config.
  6. Enter a model name and select any tables or views you would like to include in the model.

Using the entity you created, you can now perform select commands. For example:

HPCCEntities context = new HPCCEntities(); var hpcc::test::ordersQuery = from hpcc::test::orders in context.hpcc::test::orders select hpcc::test::orders; foreach (var result in hpcc::test::ordersQuery) { Console.WriteLine("{0} {1} ", result.Id, result.CustomerName); }

See "LINQ and Entity Framework" chapter in the help documentation for example queries of the supported LINQ.