[jira] [Commented] (FLINK-20447) Querying grouy by PK does not work
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https://issues.apache.org/jira/browse/FLINK-20447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17242886#comment-17242886
]
Zhenwei Feng commented on FLINK-20447:
--
Hi Jark,
After I reconsidered the problem, I agree with you. SQL like "select * from
table group by pk" is meaningless to some extent. Actually what I'd like to
achieve is to create a table in which the data would be updated by PK
continously(a snapshot table).
I've found the new pattern 'Upsert Kafka' in the doc v1.12, which may solve my
problem.
> Querying grouy by PK does not work
> --
>
> Key: FLINK-20447
> URL: https://issues.apache.org/jira/browse/FLINK-20447
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / API
>Affects Versions: 1.11.2
>Reporter: Zhenwei Feng
>Priority: Major
>
> Since PRIMARY KEY is unique, it should be feasible to screen columns by PK.
> The problem could be reproduced by creating a simple table:
> {code:java}
> CREATE TABLE test_table(
> Code STRING,
> Name STRING,
> ...,
> PRIMARY KEY (Code) NOT ENFORCED
> )WITH (...)
> {code}
> then parsing a SQL statement `SELECT *FROM test_table GROUP BY Code`. An
> exception as below will be thrown:
>
> {code:java}
> org.apache.calcite.sql.validate.SqlValidatorException: Expression
> 'test_table.Name' is not being grouped
> {code}
>
>
>
>
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[jira] [Commented] (FLINK-20447) Querying grouy by PK does not work
[
https://issues.apache.org/jira/browse/FLINK-20447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17242456#comment-17242456
]
Jark Wu commented on FLINK-20447:
-
Even if {{Code}} is the primary key, you still have to wrap non-grouped-fields
in agg functions (e.g. MAX, MIN), or group by all the fields, because this is
**syntax**.
Primary key is just used for optimization, e.g. the optimizer can remove
useless aggregations.
> Querying grouy by PK does not work
> --
>
> Key: FLINK-20447
> URL: https://issues.apache.org/jira/browse/FLINK-20447
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / API
>Affects Versions: 1.11.2
>Reporter: Zhenwei Feng
>Priority: Major
>
> Since PRIMARY KEY is unique, it should be feasible to screen columns by PK.
> The problem could be reproduced by creating a simple table:
> {code:java}
> CREATE TABLE test_table(
> Code STRING,
> Name STRING,
> ...,
> PRIMARY KEY (Code) NOT ENFORCED
> )WITH (...)
> {code}
> then parsing a SQL statement `SELECT *FROM test_table GROUP BY Code`. An
> exception as below will be thrown:
>
> {code:java}
> org.apache.calcite.sql.validate.SqlValidatorException: Expression
> 'test_table.Name' is not being grouped
> {code}
>
>
>
>
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