ClickHouse / ClickHouse/clickhouse-connect
Return column structure in case of empty resultset
- Dominant language
- Python
- Stars
- 521
- Forks
- 159
- Avg merge
- 1d 7h
- Merged PRs (30d)
- 46
Description
### Describe the bug
Return column structure in case of empty resultset
### Steps to reproduce
1. Use the following query "SELECT 1 as 'column1' LIMIT 0"
### Expected behaviour
Have a new setting, which will change behaviour in case of an empty result set being returned.
In case of pandas, `driver.query_df(ch_query)` should return `pd.DataFrame({'column1' : [] })`
This was resolved in the previous driver here https://github.com/ClickHouse/ClickHouse/issues/33522
Contributor guide
Research direction
Start with the query_df entry point and its handling of empty result sets, then compare the intended behavior with ClickHouse issue #33522. Done means SELECT 1 AS 'column1' LIMIT 0 can return a pandas DataFrame containing column1 with no rows, controlled by the requested setting.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- pandas, python, sql
- Domain
- database
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100