Sending HTTP POST request from SQL Server 2012 or SQL CLR C#

dennis picture dennis · Feb 10, 2015 · Viewed 10.8k times · Source

Is there a generally accepted standard way for sending HTTP requests from SQL Server 2012?

What I am trying to do is to use a remote server to process a search query and then insert the results back into the SQL Server 2012 database. The remote server offers a web api that accepts POST requests, with JSON content.

I have a working solution, which however requires to load several assemblies into SQL Server. Some of these assemblies are not fully supported (e.g. System.Net.Http.dll), giving a warning like this:

Warning: The Microsoft .NET Framework assembly 'system.net.http, version=4.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a, processorarchitecture=msil.' you are registering is not fully tested in the SQL Server hosted environment and is not supported. In the future, if you upgrade or service this assembly or the .NET Framework, your CLR integration routine may stop working. Please refer SQL Server Books Online for more details.

I was wondering if there is a better/safer way which does not require to load all these assemblies?

CLR code for my stored procedure:

[Microsoft.SqlServer.Server.SqlProcedure]
public static void SendSearchRequestProcedure (string query, string table)
{
    RunAsync(query,table).Wait();
}

static async Task RunAsync(string query, string table)
{
    using (var client = new HttpClient())
    {
        HttpResponseMessage response;

        client.BaseAddress = new Uri("http://localhost:9000/");
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        var search = new Search() { Query = query, Table = table };

        response = await client.PostAsJsonAsync("api/search/", search);

        if (!response.IsSuccessStatusCode)
        {
            // handle error
        }
    }
} 

Answer

dennis picture dennis · Feb 10, 2015

Like Joe suggested using HttpWebRequest instead of HttpClient works without having to use unsupported assemblies:

[Microsoft.SqlServer.Server.SqlProcedure]
public static void SendRequest (string query, string table)
{
    string address = "http://localhost:9000/api/search";
    HttpWebRequest request = (HttpWebRequest) WebRequest.Create(address);
    request.ContentType = "application/json; charset=utf-8";
    request.Method = "POST";

    using (var streamWriter = new StreamWriter(request.GetRequestStream()))
    {
        string json = "{\"Query\":\""+query+"\",\"Table\":\""+table+"\"}";

        streamWriter.Write(json);
        streamWriter.Flush();
    }

    var httpResponse = (HttpWebResponse)request.GetResponse();
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        var result = streamReader.ReadToEnd();
    }
}