You can use the SELECT INTO statement to export formatted data to a file.

Data Export with an SQL Query

The following query exports data into a file formatted in comma-separated values (CSV):

C#

String connectionString = "User=admin;APIToken=myApiToken;Url=https://yoursitename.atlassian.net";

using (JIRAConnection connection = new JIRAConnection(connectionString)) {
  JIRACommand cmd = new JIRACommand("SELECT Key, Name INTO [csv://Projects.txt] FROM [Projects] WHERE Id = '10000' ", connection);
  int rowsAffected = cmd.ExecuteNonQuery();
} 

VB.NET

Dim connectionString As [String] = "User=admin;APIToken=myApiToken;Url=https://yoursitename.atlassian.net" 

Using connection As New JIRAConnection(connectionString)
  Dim cmd As New JIRACommand("SELECT Key, Name INTO [csv://Projects.txt] FROM [Projects] WHERE Id = '10000'", connection)
  Dim rowsAffected As Integer = cmd.ExecuteNonQuery()
End Using

You can specify other file formats in the URI. The following example exports tab-separated values:

C#

String connectionString = "User=admin;APIToken=myApiToken;Url=https://yoursitename.atlassian.net";

using (JIRAConnection connection = new JIRAConnection(connectionString)) {
  JIRACommand cmd = new JIRACommand("SELECT * INTO [Projects] IN [csv://filename=c:/Projects.csv;delimiter=tab] FROM [Projects] WHERE Id = '10000'", connection);
  int rowsAffected = cmd.ExecuteNonQuery();
} 

VB.NET

Dim connectionString As [String] = "User=admin;APIToken=myApiToken;Url=https://yoursitename.atlassian.net" 

Using connection As New JIRAConnection(connectionString)
  Dim cmd As New JIRACommand("SELECT * INTO [Projects] IN [csv://filename=c:/Projects.csv;delimiter=tab] FROM [Projects] WHERE Id = '10000'", connection)
  Dim rowsAffected As Integer = cmd.ExecuteNonQuery()
End Using