fix

Author: zhanglistar

cpp-ch/local-engine/Common/CHUtil.cpp

@@ -151,6 +151,17 @@ BlockUtil::convertColumnAsNecessary(const DB::ColumnWithTypeAndName & column, co
         DB::JoinCommon::convertColumnToNullable(nullable_column);
         return {nullable_column.column, sample_column.type, sample_column.name};
     }
+    else if (!sample_column.type->isNullable() && column.type->isNullable() && sample_column.type->equals(*DB::removeNullable(column.type)))
+    {
+        const auto * nullable_column = DB::checkAndGetColumn<DB::ColumnNullable>(column.column.get());
+        if (!nullable_column || std::ranges::any_of(nullable_column->getNullMapData(), [](UInt8 is_null) { return is_null != 0; }))
+            throw DB::Exception(
+                DB::ErrorCodes::LOGICAL_ERROR,
+                "Cannot convert nullable column with NULL values to non-nullable type. original:{} expected:{}",
+                column.dumpStructure(),
+                sample_column.dumpStructure());
+        return {nullable_column->getNestedColumnPtr(), sample_column.type, sample_column.name};
+    }
     else
         throw DB::Exception(
             DB::ErrorCodes::LOGICAL_ERROR,

cpp-ch/local-engine/tests/gtest_local_engine.cpp

@@ -18,7 +18,11 @@
 #include <iostream>
 #include <incbin.h>
 
+#include <Columns/ColumnNullable.h>
+#include <Columns/ColumnsNumber.h>
 #include <Disks/DiskLocal.h>
+#include <DataTypes/DataTypeNullable.h>
+#include <DataTypes/DataTypeString.h>
 #include <Formats/FormatFactory.h>
 #include <Interpreters/Context.h>
 #include <Interpreters/registerInterpreters.h>
@@ -59,6 +63,36 @@ TEST(TESTUtil, TestByteToLong)
     ASSERT_EQ(expected, result);
 }
 
+TEST(BlockUtil, ConvertNullableColumnAsNecessary)
+{
+    auto string_type = std::make_shared<DataTypeString>();
+    auto nullable_string_type = std::make_shared<DataTypeNullable>(string_type);
+
+    auto nested = string_type->createColumn();
+    nested->insert("A");
+    nested->insert("B");
+    auto null_map = ColumnUInt8::create(2, 0);
+    ColumnWithTypeAndName nullable_column(
+        ColumnNullable::create(std::move(nested), std::move(null_map)), nullable_string_type, "col_1");
+    ColumnWithTypeAndName sample_column(string_type, "broadcast_right_col_1");
+
+    auto converted = BlockUtil::convertColumnAsNecessary(nullable_column, sample_column);
+    ASSERT_TRUE(converted.type->equals(*string_type));
+    ASSERT_EQ("broadcast_right_col_1", converted.name);
+    ASSERT_FALSE(converted.column->isNullable());
+
+    auto nested_with_null = string_type->createColumn();
+    nested_with_null->insert("A");
+    nested_with_null->insertDefault();
+    auto null_map_with_null = ColumnUInt8::create();
+    null_map_with_null->insertValue(0);
+    null_map_with_null->insertValue(1);
+    ColumnWithTypeAndName nullable_column_with_null(
+        ColumnNullable::create(std::move(nested_with_null), std::move(null_map_with_null)), nullable_string_type, "col_1");
+
+    ASSERT_THROW(BlockUtil::convertColumnAsNecessary(nullable_column_with_null, sample_column), DB::Exception);
+}
+
 TEST(ReadBufferFromFile, seekBackwards)
 {
     static constexpr size_t N = 256;
@@ -110,4 +144,4 @@ int main(int argc, char ** argv)
 
     ::testing::InitGoogleTest(&argc, argv);
     return RUN_ALL_TESTS();
-}
+}