diff --git a/dbms/src/Debug/MockTiDB.cpp b/dbms/src/Debug/MockTiDB.cpp
index 2e7822a8bbf..d777820c6fa 100644
--- a/dbms/src/Debug/MockTiDB.cpp
+++ b/dbms/src/Debug/MockTiDB.cpp
@@ -25,7 +25,7 @@ using Table = MockTiDB::Table;
 using TablePtr = MockTiDB::TablePtr;
 
 Table::Table(const String & database_name_, const String & table_name_, TableInfo && table_info_)
-    : table_info(std::move(table_info_)), database_name(database_name_), table_name(table_name_)
+    : table_info(std::move(table_info_)), database_name(database_name_), table_name(table_name_), col_id(table_info_.columns.size())
 {}
 
 MockTiDB::MockTiDB() { databases["default"] = 0; }
@@ -325,7 +325,7 @@ void MockTiDB::addColumnToTable(const String & database_name, const String & tab
         != columns.end())
         throw Exception("Column " + column.name + " already exists in TiDB table " + qualified_name, ErrorCodes::LOGICAL_ERROR);
 
-    ColumnInfo column_info = getColumnInfoFromColumn(column, columns.back().id + 1);
+    ColumnInfo column_info = getColumnInfoFromColumn(column, table->allocColumnID());
     columns.emplace_back(column_info);
 
     version++;
diff --git a/dbms/src/Debug/MockTiDB.h b/dbms/src/Debug/MockTiDB.h
index 2ea55380a05..d2b8e6eeb33 100644
--- a/dbms/src/Debug/MockTiDB.h
+++ b/dbms/src/Debug/MockTiDB.h
@@ -33,6 +33,8 @@ class MockTiDB : public ext::singleton<MockTiDB>
 
         TableID id() { return table_info.id; }
 
+        ColumnID allocColumnID() { return ++col_id; }
+
         bool isPartitionTable() { return table_info.is_partition_table; }
 
         std::vector<TableID> getPartitionIDs()
@@ -48,6 +50,7 @@ class MockTiDB : public ext::singleton<MockTiDB>
     private:
         const String database_name;
         const String table_name;
+        ColumnID col_id;
     };
     using TablePtr = std::shared_ptr<Table>;
 
diff --git a/dbms/src/Storages/Transaction/SchemaBuilder.cpp b/dbms/src/Storages/Transaction/SchemaBuilder.cpp
index f0196f4247f..8dcdfe00117 100644
--- a/dbms/src/Storages/Transaction/SchemaBuilder.cpp
+++ b/dbms/src/Storages/Transaction/SchemaBuilder.cpp
@@ -43,18 +43,20 @@ inline AlterCommands detectSchemaChanges(Logger * log, const TableInfo & table_i
 
     /// Detect new columns.
     // TODO: Detect rename columns.
-    for (const auto & column_info : table_info.columns)
+
+    /// Detect dropped columns.
+    for (const auto & orig_column_info : orig_table_info.columns)
     {
-        const auto & orig_column_info = std::find_if(orig_table_info.columns.begin(),
-            orig_table_info.columns.end(),
-            [&](const TiDB::ColumnInfo & orig_column_info_) { return orig_column_info_.id == column_info.id; });
+        const auto & column_info = std::find_if(table_info.columns.begin(),
+            table_info.columns.end(),
+            [&](const TiDB::ColumnInfo & column_info_) { return column_info_.id == orig_column_info.id; });
 
         AlterCommand command;
-        if (orig_column_info == orig_table_info.columns.end())
+        if (column_info == table_info.columns.end())
         {
-            // New column.
-            command.type = AlterCommand::ADD_COLUMN;
-            setAlterCommandColumn(log, command, column_info);
+            // Dropped column.
+            command.type = AlterCommand::DROP_COLUMN;
+            command.column_name = orig_column_info.name;
         }
         else
         {
@@ -65,19 +67,18 @@ inline AlterCommands detectSchemaChanges(Logger * log, const TableInfo & table_i
         alter_commands.emplace_back(std::move(command));
     }
 
-    /// Detect dropped columns.
-    for (const auto & orig_column_info : orig_table_info.columns)
+    for (const auto & column_info : table_info.columns)
     {
-        const auto & column_info = std::find_if(table_info.columns.begin(),
-            table_info.columns.end(),
-            [&](const TiDB::ColumnInfo & column_info_) { return column_info_.id == orig_column_info.id; });
+        const auto & orig_column_info = std::find_if(orig_table_info.columns.begin(),
+            orig_table_info.columns.end(),
+            [&](const TiDB::ColumnInfo & orig_column_info_) { return orig_column_info_.id == column_info.id; });
 
         AlterCommand command;
-        if (column_info == table_info.columns.end())
+        if (orig_column_info == orig_table_info.columns.end())
         {
-            // Dropped column.
-            command.type = AlterCommand::DROP_COLUMN;
-            command.column_name = orig_column_info.name;
+            // New column.
+            command.type = AlterCommand::ADD_COLUMN;
+            setAlterCommandColumn(log, command, column_info);
         }
         else
         {
diff --git a/tests/mutable-test/txn_schema/alter_on_read.test b/tests/mutable-test/txn_schema/alter_on_read.test
index 1bd8b82102f..583df2e92a4 100644
--- a/tests/mutable-test/txn_schema/alter_on_read.test
+++ b/tests/mutable-test/txn_schema/alter_on_read.test
@@ -164,7 +164,39 @@ Code: 49. DB::Exception: Received from {#WORD} DB::Exception: Detected overflow
 => select col_2 from default.test
 Received exception from server (version {#WORD}):
 Code: 47. DB::Exception: Received from {#WORD} DB::Exception: Unknown identifier: col_2.
+=> DBGInvoke __add_column_to_tidb_table(default, test, 'col_2 Nullable(Int8)')
+=> DBGInvoke __refresh_schemas()
+=> select col_2 from default.test
+┌─col_2─┐
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+│    \N │
+└───────┘
+=> DBGInvoke __reset_schemas()
+=> DBGInvoke __drop_column_from_tidb_table(default, test, col_2)
+
+=> DBGInvoke __add_column_to_tidb_table(default, test, 'col_2 Int8')
 
+=> DBGInvoke __refresh_schemas()
+
+=> select col_2 from default.test
+┌─col_2─┐
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+│     0 │
+└───────┘
 # Clean up.
 => DBGInvoke __drop_tidb_table(default, test)
 => drop table if exists default.test