ADO.NET Provider for Azure Data Lake Storage

Build 20.0.7654

Result Sets

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 ADLSDataReader 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 = "Schema=ADLSGen2;Account=MyStorageAccount;FileSystem=MyBlobContainer;AccessKey=myAccessKey;";

using (ADLSConnection conn = new ADLSConnection(connectionString)) {
  ADLSCommand cmd = new ADLSCommand("SELECT * FROM Resources WHERE Type = 'FILE'", conn);
  ADLSDataReader 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 = "Schema=ADLSGen2;Account=MyStorageAccount;FileSystem=MyBlobContainer;AccessKey=myAccessKey;"

Using conn As New ADLSConnection(connectionString)
  Dim cmd As New ADLSCommand("SELECT * FROM Resources WHERE Type = 'FILE'", conn)
  Dim rdr As ADLSDataReader = 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

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Build 20.0.7654