ADO.NET Provider for HDFS

Build 21.0.7930

Calling Stored Procedures

You can invoke a stored procedure using HDFSCommand in the same way as any other SQL stored procedure. To instantiate a HDFSCommand object, provide the name of the stored procedure and a HDFSConnection instance as arguments to the constructor. Set the value of the CommandType property to "StoredProcedure" and add the parameters as key-value pairs to the Parameters collection of the HDFSCommand instance.

C#

string connectionString = "Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;";

using (HDFSConnection connection = new HDFSConnection(connectionString)) {
  HDFSCommand cmd = new HDFSCommand("Open", connection);
  cmd.CommandType = CommandType.StoredProcedure; 
  cmd.Parameters.Add(new HDFSParameter("@Path", "/user/root/test/new.txt"));
  // Add other parameters as needed ...

  HDFSDataReader rdr = cmd.ExecuteReader();
  while (rdr.Read()) {
    for (int i = 0; i < rdr.FieldCount; i++) {
      Console.WriteLine(rdr.GetName(i) + " --> " + rdr[i]);
    }
    Console.WriteLine();
  }
}

VB.NET

Dim connectionString As String = "Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;"

Using connection As New HDFSConnection(connectionString)
  Dim cmd As New HDFSCommand("Open", connection)
  cmd.CommandType = CommandType.StoredProcedure
  cmd.Parameters.Add(New HDFSParameter("@Path", "/user/root/test/new.txt"))
  ' Add other parameters as needed ...

  Dim rdr As HDFSDataReader = cmd.ExecuteReader()
  While rdr.Read()
	  For i As Integer = 0 To rdr.FieldCount - 1
		  Console.WriteLine(rdr.GetName(i) + " --> " + rdr(i))
	  Next
	  Console.WriteLine()
  End While
End Using

Alternatively, you can set the parameters of a stored procedure in the text of the command. The support for stored procedure statements follows the standard form shown below:

"EXECUTE my_proc @first = 1, @second = 2, @third = 3;"

"EXEC my_proc @first = 1, @second = 2, @third = 3;"

To execute a parameterized query, add parameters as key-value pairs to the Parameters collection of the HDFSCommand instance.

C#

string connectionString = "Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;";

using (HDFSConnection connection = new HDFSConnection(connectionString)) {
  HDFSCommand cmd = new HDFSCommand("EXECUTE Open Path = @Path;", connection); 
  cmd.Parameters.Add(new HDFSParameter("@Path", "/user/root/test/new.txt"));
  // Add other parameters as needed ...

  HDFSDataReader rdr = cmd.ExecuteReader();
  while (rdr.Read()) {
    for (int i = 0; i < rdr.FieldCount; i++) {
      Console.WriteLine(rdr.GetName(i) + " --> " + rdr[i]);
    }
    Console.WriteLine();
  }
}

VB.NET

Dim connectionString As String = "Host=sandbox-hdp.hortonworks.com;Port=50070;Path=/user/root;"

Using connection As New HDFSConnection(connectionString)
  Dim cmd As New HDFSCommand("EXECUTE Open Path = @Path;", connection)
  cmd.Parameters.Add(New HDFSParameter("@Path", "/user/root/test/new.txt"))
  ' Add other parameters as needed ...

  Dim rdr As HDFSDataReader = cmd.ExecuteReader()
  While rdr.Read()
	  For i As Integer = 0 To rdr.FieldCount - 1
		  Console.WriteLine(rdr.GetName(i) + " --> " + rdr(i))
	  Next
	  Console.WriteLine()
  End While
End Using

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Build 21.0.7930