[ARROW-6274] [Rust] [DataFusion] Add support for writing results to CSV

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.16.0
• Component/s: Rust, Rust - DataFusion
• Labels: beginner pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/22658
• Assignee: Hengruo Zhang
• Reporter: Andy Grove
• Created: 16/Aug/19 14:26
• Updated: 11/Jan/23 07:46
• Resolved: 09/Oct/19 14:35

Description

There is currently no simple way to result query results to CSV. It would be good to have convenience methods either in ExecutionContext or separate utility methods to enable results to be written in CSV format to stdout or to a file.

There is sample code in unit tests for this and the approach is to iterate over each row in a batch and then iterate over each column and downcast it to an appropriate type (based on the schema associated with the batch) and then pull out the value for the row.

See https://github.com/apache/arrow/blob/master/rust/datafusion/tests/sql.rs#L425-L497 for example code in a test

 

 

Issue Links

• links to: GitHub Pull Request #5577