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https://issues.apache.org/jira/browse/TRAFODION-1673?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15365409#comment-15365409
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ASF GitHub Bot commented on TRAFODION-1673:
-------------------------------------------
Github user zellerh commented on a diff in the pull request:
https://github.com/apache/incubator-trafodion/pull/577#discussion_r69836669
--- Diff: core/sql/parser/sqlparser.y ---
@@ -7001,6 +7036,46 @@ rel_subquery_and_as_clause : rel_subquery as_clause
$$ = $2;
}
+with_clause_list : with_clause
+ { $$ = $1 ; }
+
+ | with_clause_list ',' correlation_name TOK_AS
rel_subquery
--- End diff --
Can we do this in a way that doesn't have two different rules for the first
and the subsequent parts of the WITH clause? See comment above for how the ANSI
standard handles the WITH clause.
> Implement the WITH clause in Trafodion SQL for simple use cases
> ---------------------------------------------------------------
>
> Key: TRAFODION-1673
> URL: https://issues.apache.org/jira/browse/TRAFODION-1673
> Project: Apache Trafodion
> Issue Type: New Feature
> Components: sql-cmp
> Reporter: Hans Zeller
> Assignee: liu ming
>
> We keep running into queries that use a WITH clause to define a temporary
> view that can be used once or multiple times in a FROM clause in the query.
> For non-recursive queries, the WITH clause could probably be handled very
> similar to a view. When it is defined, we create an in-memory view
> descriptor, containing the name and the definition. When it is used in a FROM
> clause, we could go through a code path similar to that of a view - bind the
> (temporary) view text and substitute it in the query. The fix could probably
> be handled entirely in the binder.
> This JIRA is *not* about recursive queries, those would require a lot more
> effort, involving many components in addition to the binder.
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