You can access the same column information about the results of a query that you can for table schemas. See Columns for the columns returned.

Retrieving Result Set Metadata

You can use the GetSchemaTable method of the AzureDevOpsDataReader to retrieve result set metadata. Call GetSchemaTable after calling ExecuteReader.

Each row of the DataTable describes a column in the query's result.

C#

string connectionString = "AuthScheme=Basic;Organization=MyAzureDevOpsOrganization;Catalog=Project_dev;Schema=Project;PersonalAccessToken=MyPAT;";

using (AzureDevOpsConnection conn = new AzureDevOpsConnection(connectionString)) {
  AzureDevOpsCommand cmd = new AzureDevOpsCommand("SELECT * FROM WorkItems WHERE Reason = 'Manual'", conn);
  AzureDevOpsDataReader rdr = cmd.ExecuteReader();
  DataTable schemaTable = rdr.GetSchemaTable();
  foreach (DataRow row in schemaTable.Rows) {
    foreach (DataColumn col in schemaTable.Columns) {
      Console.WriteLine("{0}: {1}", col.ColumnName, row[col]);
    }
  }
}

VB.NET

Dim connectionString As String = "AuthScheme=Basic;Organization=MyAzureDevOpsOrganization;Catalog=Project_dev;Schema=Project;PersonalAccessToken=MyPAT;"

Using conn As New AzureDevOpsConnection(connectionString)
  Dim cmd As New AzureDevOpsCommand("SELECT * FROM WorkItems WHERE Reason = 'Manual'", conn)
  Dim rdr As AzureDevOpsDataReader = cmd.ExecuteReader()
  Dim schemaTable As DataTable = rdr.GetSchemaTable()
  For Each row As DataRow In schemaTable.Rows
    For Each col As DataColumn In schemaTable.Columns
      Console.WriteLine("{0}: {1}", col.ColumnName, row(col))
    Next
  Next
End Using