clickhouse: add support for parsing ARRAY JOIN #982
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lustefaniak
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Thank you for the contribution @lustefaniak -- I had a comment about this one
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| let expr = self.parse_expr()?; | ||
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| let alias = self.parse_optional_table_alias(keywords::RESERVED_FOR_TABLE_ALIAS)?; |
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I am not sure about ARRAY JOIN always being a "field accessor" -- would't it makes sense to parse the argument as TableFactor and that way it can support being a table / subquery / etc rather than just an expression? That would also handle aliases as well
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I don't fully understand what TableFactor is or its purpose in the lib 🤔 I will have to give it more read.
I checked Clickhouse's latest docs and there is more syntax I need to support e.g.
SELECT s, `nest.x`, `nest.y`
FROM nested_test
ARRAY JOIN `nest.x`, `nest.y`;From what I could tell, this behaves much like UNNEST, and there are important limitations to what could be inside such ARRAY JOIN hence I'm not so sure if making it generic TableFactor actually makes sense 🤔
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I think of TableFactor as basically anything that could be JOINEd (aka show up as a element in the FROM clause)
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This one appears to be stalled. Marking as Draft until we sort out what is needed |
https://clickhouse.com/docs/en/sql-reference/statements/select/array-join