diff --git a/README.md b/README.md
index 24c95f8d7..f30d47413 100644
--- a/README.md
+++ b/README.md
@@ -566,6 +566,12 @@ The overview function flow at bbgo
 
 ### Adding new migration
 
+1. The project used rockerhopper for db migration. 
+https://github.com/c9s/rockhopper
+
+
+2. Create migration files
+
 ```sh
 rockhopper --config rockhopper_sqlite.yaml create --type sql add_pnl_column
 rockhopper --config rockhopper_mysql.yaml create --type sql add_pnl_column
@@ -577,9 +583,11 @@ or
 bash utils/generate-new-migration.sh add_pnl_column
 ```
 
-Be sure to edit both sqlite3 and mysql migration files.
+Be sure to edit both sqlite3 and mysql migration files. ( [Sample] (migrations/mysql/20210531234123_add_kline_taker_buy_columns.sql) )
 
-To test the drivers, you can do:
+
+To test the drivers, you have to update the rockhopper_mysql.yaml file to connect your database,
+then do:
 
 ```sh
 rockhopper --config rockhopper_sqlite.yaml up
diff --git a/migrations/mysql/20211204014905_update_taker_buy_base_volumn.sql b/migrations/mysql/20211204014905_update_taker_buy_base_volumn.sql
new file mode 100644
index 000000000..15d236a03
--- /dev/null
+++ b/migrations/mysql/20211204014905_update_taker_buy_base_volumn.sql
@@ -0,0 +1,21 @@
+-- +up
+-- +begin
+ALTER TABLE binance_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(32,8) NOT NULL;
+-- +end
+-- +begin
+ALTER TABLE max_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(32,8) NOT NULL;
+-- +end
+-- +begin
+ALTER TABLE okex_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(32,8) NOT NULL;
+-- +end
+
+-- +down
+-- +begin
+ALTER TABLE binance_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(16,8) NOT NULL;
+-- +end
+-- +begin
+ALTER TABLE max_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(16,8) NOT NULL;
+-- +end
+-- +begin
+ALTER TABLE okex_klines CHANGE taker_buy_base_volume taker_buy_base_volume decimal(16,8) NOT NULL;
+-- +end
diff --git a/migrations/sqlite3/20211204014905_update_taker_buy_base_volumn.sql b/migrations/sqlite3/20211204014905_update_taker_buy_base_volumn.sql
new file mode 100644
index 000000000..a88ad32d4
--- /dev/null
+++ b/migrations/sqlite3/20211204014905_update_taker_buy_base_volumn.sql
@@ -0,0 +1,8 @@
+-- +up
+-- +begin
+-- +end
+
+-- +down
+
+-- +begin
+-- +end