[ARROW-15822] [C++] Cast duration to string (thus CSV writing) not supported

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 7.0.0, 7.0.2
• Fix Version/s: 11.0.0
• Component/s: C++, R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/31263
• Assignee: Ben Harkins
• Reporter: Carl Boettiger
• Created: 02/Mar/22 04:19
• Updated: 11/Jan/23 11:39
• Resolved: 02/Nov/22 10:39

Description

Edit (Dragos Moldovan-Grünfeld): The issue I opened (ARROW-15833) is basically a duplicate of this. It's fundamentally a C++ issue that happened to surface in the R CSV writer. I hope you don't mind, I modified the components to C++

===================
Consider this reprex:

arrow::write_csv_arrow(data.frame(time = as.difftime(1, units="secs")), "test.csv")

This errors with:

Error: NotImplemented: Unsupported cast from duration[s] to utf8 using function cast_string

 

Note that readr::write_csv() has no trouble with this (which renders the data as "1" without a unit).  Arguably the readr rendering is lossy, but then we usually assume units are provided in other metadata anyway.

Issue Links

• is duplicated by: ARROW-15833 [C++] Support casting from duration to string/utf8
• links to: GitHub Pull Request #14450