Order by concurrency_key before distinct
#539
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Microsoft SQL Server requires a deterministic order when using `limit` (aka you have to provide `ORDER BY`). By default, in the MSSQL adapter, we inject a `ORDER BY [primary_key]` clause to achieve so, if not any `order` has been specified in the query. This now leads to an issue in Solid Queue, where `concurrency_key` is selected and MSSQL complains that `id` is not in its `SELECT` clause. I first looked into fixing this in the SQL adapter, but then found a test in `activerecord` itself (`test_pluck_and_distinct`) that orders first before calling `distinct`. So I would suggest to align Solid Queue here and order by `concurrency_key` prior to calling `distinct`. I am aware that the existing code works with SQlite, MySQL and PostgreSQL as these do not require to pass an `ORDER BY` clause with `LIMIT`. I don't think this small addition will cause any troubles on the other DBMS systems.
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Aha, good catch! Yes, I don't think this will cause any trouble with the other DBMS. Thank you! |
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Microsoft SQL Server requires a deterministic order when using
limit(aka you have to provideORDER BY). By default, in the MSSQL adapter, we inject aORDER BY [primary_key]clause to achieve so, if not anyorderhas been specified in the query.This now leads to an issue in Solid Queue, where
concurrency_keyis selected and MSSQL complains thatidis not in itsSELECTclause.I first looked into fixing this in the SQL adapter, but then found a test in
activerecorditself (test_pluck_and_distinct) that orders first before callingdistinct. So I would suggest to align Solid Queue here and order byconcurrency_keyprior to callingdistinct.I am aware that the existing code works with SQlite, MySQL and PostgreSQL as these do not require to pass an
ORDER BYclause withLIMIT. But I don't think this small addition will cause any troubles on the other DBMS systems.