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restore GLOBAL IN column renames

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This commit is contained in:
chertus 2019-03-18 21:45:49 +03:00
parent c9169b0a98
commit 913377fdaf
1 changed files with 34 additions and 0 deletions
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34
dbms/src/Interpreters/SyntaxAnalyzer.cpp
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@ -123,6 +123,37 @@ bool hasArrayJoin(const ASTPtr & ast)
return false;
}
/// Keep number of columns for 'GLOBAL IN (SELECT 1 AS a, a)'
void renameDuplicatedColumns(const ASTSelectQuery * select_query)
{
ASTs & elements = select_query->select_expression_list->children;
std::set<String> all_column_names;
std::set<String> assigned_column_names;
for (auto & expr : elements)
all_column_names.insert(expr->getAliasOrColumnName());
for (auto & expr : elements)
{
auto name = expr->getAliasOrColumnName();
if (!assigned_column_names.insert(name).second)
{
size_t i = 1;
while (all_column_names.end() != all_column_names.find(name + "_" + toString(i)))
++i;
name = name + "_" + toString(i);
expr = expr->clone(); /// Cancels fuse of the same expressions in the tree.
expr->setAlias(name);
all_column_names.insert(name);
assigned_column_names.insert(name);
}
}
}
/// Sometimes we have to calculate more columns in SELECT clause than will be returned from query.
/// This is the case when we have DISTINCT or arrayJoin: we require more columns in SELECT even if we need less columns in result.
/// Also we have to remove duplicates in case of GLOBAL subqueries. Their results are placed into tables so duplicates are inpossible.
@ -659,6 +690,9 @@ SyntaxAnalyzerResultPtr SyntaxAnalyzer::analyze(
if (select_query)
{
if (remove_duplicates)
renameDuplicatedColumns(select_query);
if (const ASTTablesInSelectQueryElement * node = select_query->join())
{
if (settings.enable_optimize_predicate_expression)