Support Enums type for MySQL engine ClickHouse#3985

BohuTANG · Jun 27, 2020 · f609fd3 · f609fd3
1 parent 3e6da7d
commit f609fd3
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Showing 2 changed files with 11 additions and 0 deletions.
diff --git a/src/Core/ExternalResultDescription.cpp b/src/Core/ExternalResultDescription.cpp
@@ -5,6 +5,7 @@
 #include <DataTypes/DataTypeString.h>
 #include <DataTypes/DataTypeUUID.h>
 #include <DataTypes/DataTypesNumber.h>
+#include <DataTypes/DataTypeEnum.h>
 #include <Common/typeid_cast.h>
 #include <ext/range.h>
 
@@ -60,6 +61,10 @@ void ExternalResultDescription::init(const Block & sample_block_)
             types.emplace_back(ValueType::vtDateTime, is_nullable);
         else if (typeid_cast<const DataTypeUUID *>(type))
             types.emplace_back(ValueType::vtUUID, is_nullable);
+        else if (typeid_cast<const DataTypeEnum8 *>(type))
+            types.emplace_back(ValueType::vtString, is_nullable);
+        else if (typeid_cast<const DataTypeEnum16 *>(type))
+            types.emplace_back(ValueType::vtString, is_nullable);
         else
             throw Exception{"Unsupported type " + type->getName(), ErrorCodes::UNKNOWN_TYPE};
     }

diff --git a/src/Storages/StorageMySQL.cpp b/src/Storages/StorageMySQL.cpp
@@ -8,6 +8,7 @@
 #include <Interpreters/evaluateConstantExpression.h>
 #include <Core/Settings.h>
 #include <Interpreters/Context.h>
+#include <DataTypes/DataTypeString.h>
 #include <DataStreams/IBlockOutputStream.h>
 #include <Formats/FormatFactory.h>
 #include <Common/parseAddress.h>
@@ -85,6 +86,11 @@ Pipes StorageMySQL::read(
     for (const String & column_name : column_names_)
     {
         auto column_data = metadata_snapshot->getColumns().getPhysical(column_name);
+
+        WhichDataType which(column_data.type);
+        /// Convert enum to string.
+        if (which.isEnum())
+            column_data.type = std::make_shared<DataTypeString>();
         sample_block.insert({ column_data.type, column_data.name });
     }