[ https://issues.apache.org/jira/browse/CALCITE-3466?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Julian Hyde resolved CALCITE-3466. ---------------------------------- Resolution: Fixed Fixed in [571cf95a|https://github.com/apache/calcite/commit/571cf95a1564c925bf73e4dae3a6c63199b17c4e]; thanks for the PR, [~wangweidong]! Regarding the structure of the code. I took [~danny0405]'s suggested restructuring, then factored the logic into a private function {{needNewSubQuery}} that returns {{boolean}}. I hope people think it is an improvement. > JDBC adapter incorrectly drops GROUP BY clause of sub-query > ----------------------------------------------------------- > > Key: CALCITE-3466 > URL: https://issues.apache.org/jira/browse/CALCITE-3466 > Project: Calcite > Issue Type: Bug > Components: jdbc-adapter > Affects Versions: 1.21.0, 1.22.0 > Reporter: Wang Weidong > Assignee: Wang Weidong > Priority: Major > Labels: pull-request-available > Fix For: 1.22.0 > > Attachments: screenshot-1.png > > Time Spent: 8h 40m > Remaining Estimate: 0h > > While convert RelNode to SqlNode, the "group by" statement in subquery was > dropped unexpectedly. For example, > original sql is: > {code:sql} > select a, avg(c1) from > ( > select a,sum(d),b as c1 from t group by b,a > ) as t > group by a > {code} > RelNode converted by SqlNode is > {code:sql} > LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)]) > LogicalProject(A=[$1], C1=[$0]) > LogicalAggregate(group=[{0, 1}], EXPR$1=[SUM($2)]) > LogicalProject(B=[$1], A=[$0], D=[$3]) > EnumerableTableScan(table=[[T_TESTPROJECTMERGE]]) > {code} > And then convert this RelNode to SqlNode, the sql of SqlNode is like this: > {code:sql} > SELECT `A`, AVG(`B`) > FROM `T` > GROUP BY `A` > {code} > We can find that "group by" in subquery was dropped which may cause SqlNode > converted by RelNode being not equivalent to RelNode. > After debugging, I've found code > at > https://github.com/apache/calcite/blob/aa98c1575762718b238af8ddd44a390607de7602/core/src/main/java/org/apache/calcite/rel/rel2sql/RelToSqlConverter.java#L333 > > calls org.apache.calcite.rel.rel2sql.SqlImplementor.Builder#setGroupBy > without judge whether "group by" already exists. > Finally, I think in this case, the main select and sub-select shouldn't be > merged. -- This message was sent by Atlassian Jira (v8.3.4#803005)