Add Template method to `R2dbcEntityTemplate` to post-process `GenericExecuteSpec` for e.g. a filter function

[mlegenovic]

Is there a way to set the fetch size for R2DBC repositories or R2dbcEntityTemplate?

With JDBC you can do it on JdbcTemplate, but the R2DBC spec only provides this on the statement level, and you can't get there.

From the R2dbcEntityTemplate you can get to the DatabaseClient, but not to the statement.

Is there a way to do this somehow?

[mp911de]

Right now, your only option would be through DatabaseClient.builder().executeFunction(…) with an execute function like executeFunction(statement -> statement.fetchSize(100).execute()).

It makes sense to introduce a template function that accepts SQL for the database client and returns a GenericExecuteSpec. This hook would allow for specifying a filter function (to post-process the Statement before running it).