Fix default value in join types with non-zero default (close #18197)

src/Interpreters/HashJoin.cpp

@@ -702,7 +702,7 @@ public:
         if (lazy_defaults_count)
         {
             for (size_t j = 0; j < right_indexes.size(); ++j)
-                columns[j]->insertManyDefaults(lazy_defaults_count);
+                JoinCommon::addDefaultValues(columns[j], type_name[j].first, lazy_defaults_count);
             lazy_defaults_count = 0;
         }
     }

src/Interpreters/MergeJoin.cpp

@@ -398,7 +398,8 @@ bool joinEquals(const Block & left_block, const Block & right_block, const Block
 }
 
 template <bool copy_left>
-void joinInequalsLeft(const Block & left_block, MutableColumns & left_columns, MutableColumns & right_columns,
+void joinInequalsLeft(const Block & left_block, MutableColumns & left_columns,
+                      const Block & right_block, MutableColumns & right_columns,
                       size_t start, size_t end)
 {
     if (end <= start)
@@ -408,9 +409,10 @@ void joinInequalsLeft(const Block & left_block, MutableColumns & left_columns, M
     if constexpr (copy_left)
         copyLeftRange(left_block, left_columns, start, rows_to_add);
 
-    /// append nulls
+    for (size_t i = 0; i < right_columns.size(); ++i)
-    for (auto & column : right_columns)
+    {
-        column->insertManyDefaults(rows_to_add);
+        JoinCommon::addDefaultValues(right_columns[i], right_block.getByPosition(i).type, rows_to_add);
+    }
 }
 
 }
@@ -696,7 +698,7 @@ void MergeJoin::joinSortedBlock(Block & block, ExtraBlockPtr & not_processed)
         }
 
         left_cursor.nextN(left_key_tail);
-        joinInequalsLeft<is_all>(block, left_columns, right_columns, left_cursor.position(), left_cursor.end());
+        joinInequalsLeft<is_all>(block, left_columns, right_columns_to_add, right_columns, left_cursor.position(), left_cursor.end());
         //left_cursor.nextN(left_cursor.end() - left_cursor.position());
 
         changeLeftColumns(block, std::move(left_columns));
@@ -773,7 +775,7 @@ bool MergeJoin::leftJoin(MergeJoinCursor & left_cursor, const Block & left_block
 
         Range range = left_cursor.getNextEqualRange(right_cursor);
 
-        joinInequalsLeft<is_all>(left_block, left_columns, right_columns, left_unequal_position, range.left_start);
+        joinInequalsLeft<is_all>(left_block, left_columns, right_columns_to_add, right_columns, left_unequal_position, range.left_start);
 
         if (range.empty())
             break;

src/Interpreters/join_common.cpp

@@ -276,6 +276,20 @@ void joinTotals(const Block & totals, const Block & columns_to_add, const Names
     }
 }
 
+void addDefaultValues(MutableColumnPtr & column, const DataTypePtr & typ, size_t count)
+{
+    if (typ->getTypeId() == column->getDataType())
+    {
+        column->insertManyDefaults(count);
+    }
+    else
+    {
+        auto default_val = typ->getDefault();
+        for (size_t i = 0; i < count; ++i)
+            column->insert(default_val);
+    }
+}
+
 }
 
 
@@ -387,9 +401,24 @@ void NotJoined::correctLowcardAndNullability(MutableColumns & columns_right)
 
 void NotJoined::addLeftColumns(Block & block, size_t rows_added) const
 {
-    /// @note it's possible to make ColumnConst here and materialize it later
     for (size_t pos : column_indices_left)
-        block.getByPosition(pos).column = block.getByPosition(pos).column->cloneResized(rows_added);
+    {
+        auto & col = block.getByPosition(pos);
+        if (col.column->getDataType() == col.type->getTypeId())
+        {
+            col.column = col.column->cloneResized(rows_added);
+        }
+        else
+        {
+            auto mut_col = col.column->cloneEmpty();
+            mut_col->reserve(rows_added);
+
+            const auto default_value = col.type->getDefault();
+            for (size_t i = 0; i < rows_added; ++i)
+                mut_col->insert(default_value);
+            col.column = std::move(mut_col);
+        }
+    }
 }
 
 void NotJoined::addRightColumns(Block & block, MutableColumns & columns_right) const

src/Interpreters/join_common.h

@@ -34,6 +34,8 @@ void checkTypesOfKeys(const Block & block_left, const Names & key_names_left, co
 void createMissedColumns(Block & block);
 void joinTotals(const Block & totals, const Block & columns_to_add, const Names & key_names_right, Block & block);
 
+void addDefaultValues(MutableColumnPtr & column, const DataTypePtr & typ, size_t count);
+
 }
 
 /// Creates result from right table data in RIGHT and FULL JOIN when keys are not present in left table.

tests/queries/0_stateless/01656_join_defaul_enum.reference

@@ -0,0 +1,36 @@
+1	First
+2	Second
+3	First
+1	First
+2	Second
+3	First
+4	Second
+2	Second
+4	Second
+2	Second
+4	Second
+1	First
+2	Second
+3	First
+1	First
+2	Second
+3	First
+4	Second
+1	First
+2	Second
+3	First
+1	First
+2	Second
+3	First
+4	Second
+2	Second
+4	Second
+2	Second
+4	Second
+1	First
+2	Second
+3	First
+1	First
+2	Second
+3	First
+4	Second

tests/queries/0_stateless/01656_join_defaul_enum.sql

@@ -0,0 +1,40 @@
+DROP DATABASE IF EXISTS test_01656;
+
+CREATE DATABASE test_01656;
+USE test_01656;
+
+DROP TABLE IF EXISTS table_key;
+DROP TABLE IF EXISTS table_with_enum;
+
+CREATE TABLE table_key (keycol UInt16) ENGINE = MergeTree() ORDER BY (keycol) PARTITION BY tuple();
+
+CREATE TABLE table_with_enum (keycol UInt16, enum_col Enum8('First' = 1,'Second' = 2))
+    ENGINE = MergeTree() ORDER BY (keycol) PARTITION BY tuple();
+
+INSERT INTO table_key VALUES (1), (2), (3);
+INSERT INTO table_with_enum VALUES (2, 'Second'), (4, 'Second');
+
+SET join_algorithm = 'hash';
+
+SELECT keycol, enum_col FROM table_key LEFT JOIN table_with_enum USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_key FULL JOIN table_with_enum USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_key RIGHT JOIN table_with_enum USING (keycol) ORDER BY keycol;
+
+SELECT keycol, enum_col FROM table_with_enum LEFT JOIN table_key USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_with_enum RIGHT JOIN table_key USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_with_enum FULL JOIN table_key USING (keycol) ORDER BY keycol;
+
+SET join_algorithm = 'partial_merge';
+
+SELECT keycol, enum_col FROM table_key LEFT JOIN table_with_enum USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_key FULL JOIN table_with_enum USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_key RIGHT JOIN table_with_enum USING (keycol) ORDER BY keycol;
+
+SELECT keycol, enum_col FROM table_with_enum LEFT JOIN table_key USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_with_enum RIGHT JOIN table_key USING (keycol) ORDER BY keycol;
+SELECT keycol, enum_col FROM table_with_enum FULL JOIN table_key USING (keycol) ORDER BY keycol;
+
+DROP TABLE IF EXISTS table_key;
+DROP TABLE IF EXISTS table_with_enum;
+
+DROP DATABASE IF EXISTS test_01656;