Fix

src/Interpreters/InterpreterSelectWithUnionQuery.cpp

@@ -31,10 +31,12 @@ namespace ErrorCodes
 }
 
 InterpreterSelectWithUnionQuery::InterpreterSelectWithUnionQuery(
-    const ASTPtr & query_ptr_, ContextPtr context_, const SelectQueryOptions & options_, const Names & required_result_column_names)
+        const ASTPtr & query_ptr_, ContextPtr context_,
+        const SelectQueryOptions & options_, const Names & required_result_column_names)
     : IInterpreterUnionOrSelectQuery(query_ptr_, context_, options_)
 {
     ASTSelectWithUnionQuery * ast = query_ptr->as<ASTSelectWithUnionQuery>();
+    bool require_full_header = ast->hasNonDefaultUnionMode();
 
     const Settings & settings = context->getSettingsRef();
     if (options.subquery_depth == 0 && (settings.limit > 0 || settings.offset > 0))
@@ -51,10 +53,7 @@ InterpreterSelectWithUnionQuery::InterpreterSelectWithUnionQuery(
     nested_interpreters.reserve(num_children);
     std::vector<Names> required_result_column_names_for_other_selects(num_children);
 
-    /// If it is UNION DISTINCT, do not filter by required_result_columns.
+    if (!require_full_header && !required_result_column_names.empty() && num_children > 1)
-    bool is_union_distinct = ast->union_mode == ASTSelectWithUnionQuery::Mode::DISTINCT;
-
-    if (!required_result_column_names.empty() && num_children > 1 && !is_union_distinct)
     {
         /// Result header if there are no filtering by 'required_result_column_names'.
         /// We use it to determine positions of 'required_result_column_names' in SELECT clause.
@@ -133,10 +132,10 @@ InterpreterSelectWithUnionQuery::InterpreterSelectWithUnionQuery(
     for (size_t query_num = 0; query_num < num_children; ++query_num)
     {
         const Names & current_required_result_column_names
-            = !is_union_distinct && query_num == 0 ? required_result_column_names : required_result_column_names_for_other_selects[query_num];
+            = query_num == 0 ? required_result_column_names : required_result_column_names_for_other_selects[query_num];
 
         nested_interpreters.emplace_back(
-            buildCurrentChildInterpreter(ast->list_of_selects->children.at(query_num), current_required_result_column_names));
+            buildCurrentChildInterpreter(ast->list_of_selects->children.at(query_num), require_full_header ? Names() : current_required_result_column_names));
     }
 
     /// Determine structure of the result.

src/Interpreters/InterpreterSelectWithUnionQuery.h

@@ -48,7 +48,6 @@ private:
 
     std::unique_ptr<IInterpreterUnionOrSelectQuery>
     buildCurrentChildInterpreter(const ASTPtr & ast_ptr_, const Names & current_required_result_column_names);
-
 };
 
 }

src/Interpreters/NormalizeSelectWithUnionQueryVisitor.cpp

@@ -11,11 +11,11 @@ namespace ErrorCodes
     extern const int EXPECTED_ALL_OR_DISTINCT;
 }
 
-void NormalizeSelectWithUnionQueryMatcher::getSelectsFromUnionListNode(ASTPtr & ast_select, ASTs & selects)
+void NormalizeSelectWithUnionQueryMatcher::getSelectsFromUnionListNode(ASTPtr ast_select, ASTs & selects)
 {
-    if (auto * inner_union = ast_select->as<ASTSelectWithUnionQuery>())
+    if (const auto * inner_union = ast_select->as<ASTSelectWithUnionQuery>())
     {
-        for (auto & child : inner_union->list_of_selects->children)
+        for (const auto & child : inner_union->list_of_selects->children)
             getSelectsFromUnionListNode(child, selects);
 
         return;
@@ -34,11 +34,28 @@ void NormalizeSelectWithUnionQueryMatcher::visit(ASTSelectWithUnionQuery & ast,
 {
     auto & union_modes = ast.list_of_modes;
     ASTs selects;
-    auto & select_list = ast.list_of_selects->children;
+    const auto & select_list = ast.list_of_selects->children;
+
+    if (select_list.empty())
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Got empty list of selects for ASTSelectWithUnionQuery");
+
+    /// Since nodes are traversed from bottom to top, we can also collect union modes from chidlren up to parents.
+    ASTSelectWithUnionQuery::UnionModesSet current_set_of_modes;
+    bool distinct_found = false;
 
     int i;
     for (i = union_modes.size() - 1; i >= 0; --i)
     {
+        current_set_of_modes.insert(union_modes[i]);
+        if (const auto * union_ast = typeid_cast<const ASTSelectWithUnionQuery *>(select_list[i + 1].get()))
+        {
+            const auto & current_select_modes = union_ast->set_of_modes;
+            current_set_of_modes.insert(current_select_modes.begin(), current_select_modes.end());
+        }
+
+        if (distinct_found)
+            continue;
+
         /// Rewrite UNION Mode
         if (union_modes[i] == ASTSelectWithUnionQuery::Mode::Unspecified)
         {
@@ -80,12 +97,18 @@ void NormalizeSelectWithUnionQueryMatcher::visit(ASTSelectWithUnionQuery & ast,
             distinct_list->union_mode = ASTSelectWithUnionQuery::Mode::DISTINCT;
             distinct_list->is_normalized = true;
             selects.push_back(std::move(distinct_list));
-            break;
+            distinct_found = true;
         }
     }
 
+    if (const auto * union_ast = typeid_cast<const ASTSelectWithUnionQuery *>(select_list[0].get()))
+    {
+        const auto & current_select_modes = union_ast->set_of_modes;
+        current_set_of_modes.insert(current_select_modes.begin(), current_select_modes.end());
+    }
+
     /// No UNION DISTINCT or only one child in select_list
-    if (i == -1)
+    if (!distinct_found)
     {
         if (auto * inner_union = select_list[0]->as<ASTSelectWithUnionQuery>();
             inner_union && inner_union->union_mode == ASTSelectWithUnionQuery::Mode::ALL)
@@ -103,6 +126,7 @@ void NormalizeSelectWithUnionQueryMatcher::visit(ASTSelectWithUnionQuery & ast,
     if (selects.size() == 1 && selects[0]->as<ASTSelectWithUnionQuery>())
     {
         ast = *(selects[0]->as<ASTSelectWithUnionQuery>());
+        ast.set_of_modes = std::move(current_set_of_modes);
         return;
     }
 
@@ -111,6 +135,7 @@ void NormalizeSelectWithUnionQueryMatcher::visit(ASTSelectWithUnionQuery & ast,
 
     ast.is_normalized = true;
     ast.union_mode = ASTSelectWithUnionQuery::Mode::ALL;
+    ast.set_of_modes = std::move(current_set_of_modes);
 
     ast.list_of_selects->children = std::move(selects);
 }

src/Interpreters/NormalizeSelectWithUnionQueryVisitor.h

@@ -21,7 +21,7 @@ public:
         const UnionMode & union_default_mode;
     };
 
-    static void getSelectsFromUnionListNode(ASTPtr & ast_select, ASTs & selects);
+    static void getSelectsFromUnionListNode(ASTPtr ast_select, ASTs & selects);
 
     static void visit(ASTPtr & ast, Data &);
     static void visit(ASTSelectWithUnionQuery &, Data &);

src/Parsers/ASTSelectWithUnionQuery.cpp

@@ -20,6 +20,7 @@ ASTPtr ASTSelectWithUnionQuery::clone() const
     res->union_mode = union_mode;
 
     res->list_of_modes = list_of_modes;
+    res->set_of_modes = set_of_modes;
 
     cloneOutputOptions(*res);
     return res;
@@ -71,4 +72,10 @@ void ASTSelectWithUnionQuery::formatQueryImpl(const FormatSettings & settings, F
     }
 }
 
+
+bool ASTSelectWithUnionQuery::hasNonDefaultUnionMode() const
+{
+    return set_of_modes.contains(Mode::DISTINCT) || set_of_modes.contains(Mode::INTERSECT) || set_of_modes.contains(Mode::EXCEPT);
+}
+
 }

src/Parsers/ASTSelectWithUnionQuery.h

@@ -14,6 +14,7 @@ public:
     String getID(char) const override { return "SelectWithUnionQuery"; }
 
     ASTPtr clone() const override;
+
     void formatQueryImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
 
     const char * getQueryKindString() const override { return "Select"; }
@@ -28,6 +29,7 @@ public:
     };
 
     using UnionModes = std::vector<Mode>;
+    using UnionModesSet = std::unordered_set<Mode>;
 
     Mode union_mode;
 
@@ -36,6 +38,11 @@ public:
     bool is_normalized = false;
 
     ASTPtr list_of_selects;
+
+    UnionModesSet set_of_modes;
+
+    /// Consider any mode other than ALL as non-default.
+    bool hasNonDefaultUnionMode() const;
 };
 
 }

tests/queries/0_stateless/02008_test_union_distinct_in_subquery.reference

@@ -1,9 +1,26 @@
 -- { echo }
 select count() from (select * from test union distinct select * from test);
+5
+select count() from (select * from test union distinct select * from test union all select * from test);
+10
+select count() from (select * from test union distinct select * from test except select * from test where name = '3');
+4
+select count() from (select * from test intersect (select * from test where toUInt8(name) < 4) union distinct (select * from test where name = '5' or name = '1') except select * from test where name = '3');
+3
+with (select count() from (select * from test union distinct select * from test except select * from test where toUInt8(name) > 3)) as max
+select count() from (select * from test union all select * from test where toUInt8(name) < max);
+7
+with (select count() from (select * from test union distinct select * from test except select * from test where toUInt8(name) > 3)) as max
+select count() from (select * from test except select * from test where toUInt8(name) < max);
 3
 select uuid from test union distinct select uuid from test;
 00000000-0000-0000-0000-000000000000
+select uuid from test union distinct select uuid from test union all select uuid from test where name = '1';
+00000000-0000-0000-0000-000000000000
+00000000-0000-0000-0000-000000000000
 select uuid from (select * from test union distinct select * from test);
 00000000-0000-0000-0000-000000000000
 00000000-0000-0000-0000-000000000000
 00000000-0000-0000-0000-000000000000
+00000000-0000-0000-0000-000000000000
+00000000-0000-0000-0000-000000000000

tests/queries/0_stateless/02008_test_union_distinct_in_subquery.sql

@@ -3,8 +3,21 @@ create table test (name String, uuid UUID) engine=Memory();
 insert into test select '1', '00000000-0000-0000-0000-000000000000';
 insert into test select '2', '00000000-0000-0000-0000-000000000000';
 insert into test select '3', '00000000-0000-0000-0000-000000000000';
+insert into test select '4', '00000000-0000-0000-0000-000000000000';
+insert into test select '5', '00000000-0000-0000-0000-000000000000';
 
 -- { echo }
 select count() from (select * from test union distinct select * from test);
+select count() from (select * from test union distinct select * from test union all select * from test);
+select count() from (select * from test union distinct select * from test except select * from test where name = '3');
+select count() from (select * from test intersect (select * from test where toUInt8(name) < 4) union distinct (select * from test where name = '5' or name = '1') except select * from test where name = '3');
+
+with (select count() from (select * from test union distinct select * from test except select * from test where toUInt8(name) > 3)) as max
+select count() from (select * from test union all select * from test where toUInt8(name) < max);
+with (select count() from (select * from test union distinct select * from test except select * from test where toUInt8(name) > 3)) as max
+select count() from (select * from test except select * from test where toUInt8(name) < max);
+
 select uuid from test union distinct select uuid from test;
+select uuid from test union distinct select uuid from test union all select uuid from test where name = '1';
 select uuid from (select * from test union distinct select * from test);
+

tests/queries/skip_list.json

@@ -507,7 +507,6 @@
         "01532_execute_merges_on_single_replica", /// static zk path
         "01530_drop_database_atomic_sync", /// creates database
         "02001_add_default_database_to_system_users", ///create user
-        "02002_row_level_filter_bug", ///create user
+        "02002_row_level_filter_bug" ///create user
-        "02008_test_union_distinct_in_subquery" /// create database
     ]
 }