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ASF GitHub Bot commented on TRAFODION-2163: ------------------------------------------- GitHub user traflm opened a pull request: https://github.com/apache/incubator-trafodion/pull/664 TRAFODION-2163 support MYSQL style function GROUP_CONCAT add new SQL syntax for pivot_group() so to allow same MySQL syntax. Also fix original pivot_group() issue and tested more. But still protected by CQD mode_special_4, since we still need more tests. So by add this MySQL syntax, we can test more real cases simpler, without modify the query to use pivot_group() The original pivot_group() has issue when rows are not sorted, its internal pointers to track each bucket's len and pos is shared. One simple fix is to disallow hash groupby for pivot_group, which used in this PR. A more complex and final fix will be to use bucket's own var for len and pos, but that needs much more modification to current groupby which never need per bucket vars, and that is only for pivot_group. So I would like to fix that later, and also need to implement the sort direction support. But this will make some real case to be supported and will simplify further tests, and can already support most commonly used CONCAT_GROUP scenarios we saw previously. You can merge this pull request into a Git repository by running: $ git pull https://github.com/traflm/incubator-trafodion TRAFODION-2157 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/incubator-trafodion/pull/664.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #664 ---- commit 1696410e6bff746a3f64ec1574f20fc0bbb93376 Author: Liu Ming <ovis_p...@sina.com> Date: 2016-08-19T06:11:27Z TRAFODION-2163 support MYSQL style function GROUP_CONCAT ---- > support MYSQL style function GROUP_CONCAT > ----------------------------------------- > > Key: TRAFODION-2163 > URL: https://issues.apache.org/jira/browse/TRAFODION-2163 > Project: Apache Trafodion > Issue Type: Sub-task > Reporter: liu ming > Assignee: liu ming > > One popular MySQL function is GROUP_CONCAT : > SELECT student_name, > GROUP_CONCAT(DISTINCT test_score > ORDER BY test_score asc SEPARATOR ' ') > FROM student > GROUP BY student_name; > Support this syntax. > This helps migration. -- This message was sent by Atlassian JIRA (v6.3.4#6332)