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https://issues.apache.org/jira/browse/FLINK-26401?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17499517#comment-17499517
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luoyuxia commented on FLINK-26401:
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[~zoucao] yes, when we talk to hive syntax compatibility in flink, it always
comes to switch to hive dialect. See more details in [link
use-hive-dialect|https://nightlies.apache.org/flink/flink-docs-release-1.13/docs/connectors/table/hive/hive_dialect/#use-hive-dialect].
And as it switches to hive dialect, the reserved keywords in flink won't be
considered to be reserved keywords anymore.
> improve the compatibility for hive catalogView
> ----------------------------------------------
>
> Key: FLINK-26401
> URL: https://issues.apache.org/jira/browse/FLINK-26401
> Project: Flink
> Issue Type: Improvement
> Components: Connectors / Hive
> Reporter: zoucao
> Priority: Major
>
> For now, many reserved keywords were kept for FlinkSQL[1], and some of them
> are different from other bigdata systems, like spark[2], hive[3]. In this
> context, users may be affected by the compatibility of various systems.
> For example, the keyword 'DATE' is marked as reserved by Flink and Hive, but
> not in spark. If the hive view is defined as
> {code:java}
> select a, b, date from hive_tb where date = '2022-02-28'
> {code}
> It will work well in spark, but in flink, the SqlParserException about ' SQL
> parse failed. Encountered "date" at line xxx, column xxx ' will be thrown.
> IIUC, If we do nothing to improve the compatibility, users must change the
> query about the hive view to
> {code:java}
> select a, b, `date` from hive_tb where `date` = '2022-02-28'
> {code}
> , to make Flink work.
> I think we can add a converter to surround reserved keywords with backticks
> before parsing.
> [1]
> https://nightlies.apache.org/flink/flink-docs-master/docs/dev/table/sql/overview/
> [2]
> https://spark.apache.org/docs/3.2.1/sql-ref-ansi-compliance.html#sql-keywords
> [3]
> https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-Keywords,Non-reservedKeywordsandReservedKeywords
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