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https://issues.apache.org/jira/browse/FLINK-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15352236#comment-15352236
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ASF GitHub Bot commented on FLINK-3943:
---------------------------------------
Github user wuchong commented on a diff in the pull request:
https://github.com/apache/flink/pull/2169#discussion_r68689676
--- Diff: docs/apis/table.md ---
@@ -873,7 +920,7 @@ val result = tableEnv.sql(
#### Limitations
-The current version of streaming SQL only supports `SELECT`, `FROM`,
`WHERE`, and `UNION` clauses. Aggregations or joins are not supported yet.
+The current version of streaming SQL only supports `SELECT`, `FROM`,
`WHERE`, `UNION` and `EXCEPT` clauses. Aggregations or joins are not supported
yet.
--- End diff --
It seems that Stream SQL hasn't supported `EXCEPT`.
> Add support for EXCEPT (set minus)
> ----------------------------------
>
> Key: FLINK-3943
> URL: https://issues.apache.org/jira/browse/FLINK-3943
> Project: Flink
> Issue Type: New Feature
> Components: Table API & SQL
> Affects Versions: 1.1.0
> Reporter: Fabian Hueske
> Assignee: Ivan Mushketyk
> Priority: Minor
>
> Currently, the Table API and SQL do not support EXCEPT.
> EXCEPT can be executed as a coGroup on all fields that forwards records of
> the first input if the second input is empty.
> In order to add support for EXCEPT to the Table API and SQL we need to:
> - Implement a {{DataSetMinus}} class that translates an EXCEPT into a DataSet
> API program using a coGroup on all fields.
> - Implement a {{DataSetMinusRule}} that translates a Calcite {{LogicalMinus}}
> into a {{DataSetMinus}}.
> - Extend the Table API (and validation phase) to provide an except() method.
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