GitHub user dosubot[bot] added a comment to the discussion: 422 Unprocessable Entity while syncing the columns from hydrolix using clickhouse connect driver
<!-- Answer --> Superset does not explicitly handle ClickHouse/Hydrolix columns of type `NULLABLE(...)` during sync. When the ClickHouse Connect driver returns types like `Nullable(Int32)`, Superset tries to match them against its type patterns, which expect simple types like `Int32`. Because `Nullable(Int32)` doesn't match, Superset marks the column as `UNKNOWN`, which can trigger a 422 Unprocessable Entity error during sync if those columns are required or used for time-based features. There is no built-in way to override this in the UI or API—column types are inferred directly from the database metadata and engine spec mappings. The recommended fix is to ensure your Hydrolix schema uses explicit, supported types (like `TIMESTAMP` or `DATETIME`) instead of leaving columns as NULLABLE or with ambiguous types. If you can't change the schema, you would need to patch the engine spec to handle `NULLABLE` types by stripping the wrapper before type mapping, but this requires backend code changes. More details and references are in this discussion: [Superset Discussion 35188](https://github.com/apache/superset/discussions/35188). <!-- Dosu Comment Footer --> *To reply, just mention [@dosu](https://go.dosu.dev/dosubot).* --- <sup>How did I do? [Good](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=great_response) | [Irrelevant](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=irrelevant_answer) | [Incorrect](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=incorrect_sources) | [Verbose](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=too_verbose) | [Hallucination](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=hallucination) | [Report 🐛](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=bug_report) | [Other](https://app.dosu.dev/response-feedback/274236f9-fd27-43a7-bf3b-8841969dc287?feedback_type=other)</sup> [](https://app.dosu.dev/a28d3c7e-a9d3-459e-9fb6-3a6f9ff4f357/ask?utm_source=github)& nbsp;[](https://go.dosu.dev/discord-bot) [](https://twitter.com/intent/tweet?text=%40dosu_ai%20helped%20me%20solve%20this%20issue!&url=https%3A//github.com/apache/superset/discussions/35230) GitHub link: https://github.com/apache/superset/discussions/35230#discussioncomment-14478540 ---- This is an automatically sent email for notifications@superset.apache.org. To unsubscribe, please send an email to: notifications-unsubscr...@superset.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: notifications-unsubscr...@superset.apache.org For additional commands, e-mail: notifications-h...@superset.apache.org
