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Continue fixing #36199.

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Nikolai Kochetov 2022-05-10 11:33:48 +00:00 committed by vdimir
parent 425d429044
commit 1feba64a4e
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3 changed files with 38 additions and 0 deletions
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32
src/Interpreters/join_common.cpp
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@ -733,6 +733,38 @@ Block NotJoinedBlocks::read()
copySameKeys(result_block);
correctLowcardAndNullability(result_block);
/// This is a very dirty hack.
/// Sometimes, columns from right joined table may be duplicating, and we can't properly process it.
/// So, in case if column is empty in result, try to find non-empty column with the same name.
/// Repro:
/// select * from (select 2 as x) as t1 right join (select count('x'), count('y'), 0 as x) as t2 on t1.x = t2.x
///
/// Please, somebody, fix it in a proper way.
{
std::unordered_map<std::string, std::list<size_t>> result_block_positions;
for (size_t i = 0; i < result_block.columns(); ++i)
{
const auto & col = result_block.getByPosition(i);
result_block_positions[col.name].push_back(i);
}
for (auto & col : result_block)
{
if (col.column->empty())
{
for (auto pos : result_block_positions[col.name])
{
const auto & same_col = result_block.getByPosition(pos);
if (!same_col.column->empty())
{
col.column = same_col.column;
break;
}
}
}
}
}
#ifndef NDEBUG
assertBlocksHaveEqualStructure(result_block, result_sample_block, "NotJoinedBlocks");
#endif

2
tests/queries/0_stateless/02267_join_dup_columns_issue36199.reference
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@ -1,2 +1,4 @@
2 1 2
0 1 0
2 1 2
0 1 0

4
tests/queries/0_stateless/02267_join_dup_columns_issue36199.sql
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@ -5,9 +5,13 @@ FROM ( SELECT 2 AS x ) AS t1
RIGHT JOIN ( SELECT count('x'), count('y'), 2 AS x ) AS t2
ON t1.x = t2.x;
select * from (select 2 as x) as t1 right join (select count('x'), count('y'), 0 as x) as t2 on t1.x = t2.x;
set join_algorithm = 'partial_merge';
SELECT *
FROM ( SELECT 2 AS x ) AS t1
RIGHT JOIN ( SELECT count('x'), count('y'), 2 AS x ) AS t2
ON t1.x = t2.x;
select * from (select 2 as x) as t1 right join (select count('x'), count('y'), 0 as x) as t2 on t1.x = t2.x;