Hello All, It seems to me this is mostly out of bounds for Commons CSV and more the province of a JDBC driver, which Commons CSV definitely is not and has never aimed to be.
Gary On Wed, Aug 14, 2024, 3:39 AM Dávid Szigecsán <sige...@gmail.com> wrote: > Hi All, > > There is a JIRA feature request ( > https://issues.apache.org/jira/browse/CSV-293) for supporting multiple > null > strings, not just one. > > To be honest, I did not really know much about the mentioned CSVW > definitions, but based on the comment in the ticket "Feel free to provide a > PR on GitHub" and the requested change seemed not a big deal to me. So I > created the PR (https://github.com/apache/commons-csv/pull/456). > > After I created it, things have changed. I got a comment on github > from Gary to check the comment in JIRA. > He explained two concerns about the feature. So I started to dig into the > topic and learn a bit about the CSVW. > > I think Gary has a point. This particular feature is far too little to > support CSVW. > As I understand it, CSVW introduces a lot of (let's say) validation rules > (in a json metadata file) that are not really needed for a "simple" CSV > parser. > E.g.: > - it introduces a feature to represent data like relational databases with > multiple CSV files and calls them TableGroup. > - the TableGroup contains multiple tables (CSV files) which are in > relation. There are keys (ForeignKey, PrimaryKey). > - there are Data Types (string as a base, but there are multiple number > integer, non negative integer, float, boolean, date, datetime, etc.) > - fields can be required > And much more. > > So the feature to support multiple null values is not enough for supporting > CSVW at all. And I agree with Gary. I can't see the real life use case > where multiple null values were used in a simple single CSV file. > Maybe in a tableGroup with multiple CSV files in a CSVW dataset it is > useful (because the different files could contain different null values), > but not in the level of a CSV file parser handles a single file. > > What do you think? > > Regards, > David >
