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LINQ to Teradata

visibility 1,568 comment 0 access_time 13 months ago

In my previous post, I demonstrated how to use ADO.NET to connect to Teradata in your OLTP projects.  In this sample, I am going to implement the same sample using ADO.NET Entity Model, Entity Framework and LINQ.

Connect to Teradata Database via .NET Data Provider

Prerequisites

Step 1 Create ADO.NET Entity Data Model

In the wizard, create ‘TDSample.edmx’ through item ‘ADO.NET Entity Data Model’.

image

Select Generate from Database:

image

Create a connection to Teradata database:

image

Remember to set the option ‘Use X Views’ to false and set the Database to the database you are using. I also changed the timeout options as my local VM responds slowly.

The entity connection string looks like:

metadata=res://*/TDSample.csdl|res://*/TDSample.ssdl|res://*/TDSample.msl;provider=Teradata.Client.Provider;provider connection string="connection timeout=90;database=TD_MS_SAMPLE_DB;user id=dbc;data source=192.168.121.128;persist security info=True;use x views=False;restrict to default database=True;command timeout=90"

* Change the server and user id/password to yours.

Click next to choose the entity framework version.

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And then choose the right tables required.

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Click Finish button to close the wizard. In my sample, the model has two tables added.

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Step 2 LINQ to Teradata

With the generated entity objects, it will be very straightforward to query from the database.

The sample code looks like:

static void Main(string[] args)
        {
            DisplayEmployeeInfoFromTeraData2();
            Console.ReadLine();

        }

        private static void DisplayEmployeeInfoFromTeraData2()
        {
            var db = new TDSampleContainer();
            var query = from emp in db.Employees.AsQueryable()
                        select new
                        {
                            EmployeeID = emp.EmployeeID,
                            EmployeeName = emp.EmployeeName,
                            EmployeeSalutation = emp.Gendar == "M" ? "Dear MR " + emp.EmployeeName :
                                      "Dear MS " + emp.EmployeeName
                        };
            foreach (var e in query)
            {
                Console.WriteLine("EmployeeID = {0}", e.EmployeeID);
                Console.WriteLine("EmployeeName = {0}", e.EmployeeName);
                Console.WriteLine("Employee Salutation = {0}", e.EmployeeSalutation);
                Console.WriteLine();
            }

            Console.WriteLine("{0} Records", query.Count());
        }

The result

image

Summary

With .NET Data Provider for Teradata, you can easily operate on the database with Linq. If you want to learn more about LINQ, please visit the following link:

https://msdn.microsoft.com/en-us/library/bb397926.aspx

info Last modified by Raymond 13 months ago copyright This page is subject to Site terms.

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