[flash-835]fix bugs that rename column after adding a column (#396)

* [flash-835]fix bugs that rename column after adding a column

* address comment

dbms/src/Storages/AlterCommands.cpp

@@ -177,7 +177,15 @@ void AlterCommand::apply(ColumnsDescription & columns_description) const
         {
             throw Exception("Rename column fails, new column name: " + column_name + " has existed ", ErrorCodes::LOGICAL_ERROR);
         }
+        String old_column_name = old_column_it->name;
         old_column_it->name = new_column_name;
+        // Change defaults value map.
+        auto default_it = columns_description.defaults.find(old_column_name);
+        if (default_it != columns_description.defaults.end())
+        {
+            columns_description.defaults.erase(default_it->first);
+            columns_description.defaults.emplace(new_column_name, default_it->second);
+        }
     }
     else
         throw Exception("Wrong parameter type in ALTER query", ErrorCodes::LOGICAL_ERROR);

dbms/src/Storages/MergeTree/MergeTreeData.cpp

@@ -1132,6 +1132,20 @@ MergeTreeData::AlterDataPartTransactionPtr MergeTreeData::renameColumnPart(
     {
         throw Exception("L0 compact does not support alter clause.");
     }
+
+    // Check if this part has column that needs to be renamed.
+    // There is one case that column cannot be found : the column is added after the table is created.
+    auto it = std::find_if(part->columns.begin(), part->columns.end(), [&](const NameAndTypePair & pair)
+    {
+        return pair.name == command.column_name;
+    });
+
+    if (it == part->columns.end())
+    {
+        LOG_INFO(log, "Not find column name " << command.column_name << " in part " << part->name);
+        return nullptr;
+    }
+
     AlterDataPartTransactionPtr transaction(new AlterDataPartTransaction(part)); /// Blocks changes to the part.
     DataPart::Checksums new_checksums = part->checksums;
 

dbms/src/Storages/StorageMergeTree.cpp

@@ -388,7 +388,8 @@ void StorageMergeTree::alterInternal(
         if (rename_column)
         {
             auto transaction = data.renameColumnPart(part, columns_for_parts, params[0]);
-            transactions.push_back(std::move(transaction));
+            if (transaction != nullptr)
+                transactions.push_back(std::move(transaction));
         }
         else if (auto transaction = data.alterDataPart(part, columns_for_parts, new_primary_key_ast, false))
             transactions.push_back(std::move(transaction));

tests/mutable-test/txn_schema/rename_column.test

@@ -179,6 +179,17 @@
 │ 2 │ test │
 └───┴──────┘
 
+# rename after add column
+=> DBGInvoke __add_column_to_tidb_table(default, test, 'k Nullable(Int8) default 0')
+=> DBGInvoke __refresh_schemas()
+=> DBGInvoke __rename_column_in_tidb_table(default, test, k, g)
+=> DBGInvoke __refresh_schemas()
+=> select a, g from default.test order by _tidb_rowid
+┌─a─┬─g─┐
+│ 1 │ 0 │
+│ 2 │ 0 │
+└───┴───┘
+
 => DBGInvoke __drop_tidb_table(default, test)
 => drop table if exists default.test
 => DBGInvoke __refresh_schemas()