diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..31b124f
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,6 @@
+TIDB_HOST='xxxxxxxx.aws.tidbcloud.com'
+TIDB_PORT='4000'
+TIDB_USER='xxxxxxxxxxx.root'
+TIDB_PASSWORD='xxxxxxx'
+TIDB_DB_NAME='test'
+CA_PATH='/etc/ssl/cert.pem'
\ No newline at end of file
diff --git a/Makefile b/Makefile
index cf22ec1..a5d82eb 100644
--- a/Makefile
+++ b/Makefile
@@ -26,28 +26,20 @@ test:
 dep:
 	pip3 install -r requirement.txt
 
-recreate-table:
-	mycli --host 127.0.0.1 --port 4000 -u root --no-warn < player_init.sql
-
 # ORMs
 peewee-test:
-	make recreate-table
 	python3 peewee_example.py
 
 sqlalchemy-test:
-	make recreate-table
 	python3 sqlalchemy_example.py
 
 # Drivers
 mysqlclient-test:
-	make recreate-table
 	python3 mysqlclient_example.py
 
 pymysql-test:
-	make recreate-table
 	python3 pymysql_example.py
 
 mysql-connector-python-test:
-	make recreate-table
 	python3 mysql_connector_python_example.py
 
diff --git a/README-zh.md b/README-zh.md
index 98a3a56..afca84b 100644
--- a/README-zh.md
+++ b/README-zh.md
@@ -4,24 +4,24 @@
 
 [English](/README.md) | 中文
 
-**tidb-example-python** 是 PingCAP 为 Python 连接 [TiDB](https://docs.pingcap.com/tidb/stable) 而编写的示例项目。你可以在这里找到以下示例：
+**tidb-example-python** 是 PingCAP 为 Python 连接 [TiDB](https://docs.pingcap.com/tidb/stable) 而编写的示例项目。其所属文档为 [TiDB 开发者文档](https://docs.pingcap.com/zh/tidb/stable/dev-guide-overview)。你可以在这里找到以下示例：
 
-**Driver**
+## Driver
 
 - [PyMySQL](/pymysql_example.py) 示例
 - [mysqlclient](/mysqlclient_example.py) 示例
 - [mysql-connector-python](/mysql_connector_python_example.py) 示例
 
-**ORM**
+## ORM
 
 - [SQLAlchemy](/sqlalchemy_example.py) 示例
 - [peewee](/peewee_example.py) 示例
 
-**Framework**
+## Framework
 
 - [Django](/django_example) 示例
 
-**Scenario**
+## Scenario
 
 - [Serverless Tier 连接](/serverless_tier_example.py)示例
 - [批量删除场景](/batch_delete.py)示例
@@ -29,11 +29,38 @@
 - [避免写偏斜](/write_skew_example.py)示例
 - [乐观/悲观事务](/txn_example.py)示例
 
-## 依赖
+## 前提要求
 
-- [TiDB](https://docs.pingcap.com/tidb/stable)
-- [mycli](https://www.mycli.net/)
-- [Python 3.6+](https://www.python.org/)
+- 已安装 [Python](https://www.python.org/)，推荐版本 3.10 及以上。
+- 启动你的 TiDB 集群，如果你还没有 TiDB 集群：
+
+  - 推荐参考[创建 TiDB Serverless 集群](https://docs.pingcap.com/zh/tidb/stable/dev-guide-build-cluster-in-cloud)文档创建你自己的 TiDB Cloud 集群。
+  - 备选参考[部署本地测试 TiDB 集群](https://docs.pingcap.com/zh/tidb/stable/quick-start-with-tidb)或[部署正式 TiDB 集群](https://docs.pingcap.com/zh/tidb/stable/production-deployment-using-tiup)文档创建本地集群。
+
+- 已获取代码并安装依赖
+
+    ```bash
+    git clone https://github.com/pingcap-inc/tidb-example-python.git
+    cd tidb-example-python
+    pip install requirement.txt
+    ```
+
+- 已正确配置代码目录下的 `.env` 配置文件，你可以用 `cp .env.example .env` 复制初始配置文件后进行更改。如果你不知道这些信息如何获取，请参考 [Obtain the connection parameters](https://docs.pingcap.com/tidbcloud/connect-via-standard-connection-serverless#obtain-the-connection-parameters) 及 [Where is the CA root path on my system?](https://docs.pingcap.com/tidbcloud/secure-connections-to-serverless-tier-clusters#where-is-the-ca-root-path-on-my-system) 文档：
+
+    ```properties
+    # TiDB 集群地址
+    TIDB_HOST='xxxxxxxx.aws.tidbcloud.com'
+    # TiDB 集群端口
+    TIDB_PORT='4000'
+    # TiDB 集群用户名
+    TIDB_USER='xxxxxxxxxxx.root'
+    # TiDB 集群密码
+    TIDB_PASSWORD='xxxxxxx'
+    # 希望本示例使用的数据库名称
+    TIDB_DB_NAME='test'
+    # 使用的 TiDB 集群如果要求使用安全连接，并使用自定义的 CA 证书时
+    CA_PATH='/etc/ssl/cert.pem'
+    ```
 
 ## 运行
 
@@ -45,22 +72,8 @@ make test
 
 ### 单独运行某项测试
 
-以 `peewee_example.py` 为例：
-
-1. 安装依赖：
+以 **peewee_example.py** 为例：`python3 peewee_example.py`。
 
-    ```bash
-    pip install -r requirement.txt
-    ```
-
-2. 初始化表
-
-    ```bash
-    mycli --host 127.0.0.1 --port 4000 -u root --no-warn < player_init.sql
-    ```
+### 预期输出
 
-3. 运行脚本
-
-    ```bash
-    python3 peewee_example.py
-    ```
\ No newline at end of file
+[预期输出](/Expected-Output.md)
diff --git a/README.md b/README.md
index 7ad6d91..465ff9a 100644
--- a/README.md
+++ b/README.md
@@ -4,24 +4,24 @@
 
 English | [中文](/README-zh.md)
 
-**tidb-example-python** is a sample project written by PingCAP for Python to connect to [TiDB](https://docs.pingcap.com/tidb/stable). You can find the following examples here.
+**tidb-example-python** is a sample project written by PingCAP for Python to connect to [TiDB](https://docs.pingcap.com/tidb/stable). This document belongs to the [TiDB developer documentation](https://docs.pingcap.com/tidb/stable/dev-guide-overview). You can find the following examples here.
 
-**Driver**
+## Driver
 
 - [PyMySQL](/pymysql_example.py) example
 - [mysqlclient](/mysqlclient_example.py) example
 - [mysql-connector-python](/mysql_connector_python_example.py) example
 
-**ORM**
+## ORM
 
 - [SQLAlchemy](/sqlalchemy_example.py) example
 - [peewee](/peewee_example.py) example
 
-**Framework**
+## Framework
 
 - [Django](/django_example) example
 
-**Scenario**
+## Scenario
 
 - [Serverless Tier connection](/serverless_tier_example.py) example
 - [Butch delete](/batch_delete.py) example
@@ -29,38 +29,51 @@ English | [中文](/README-zh.md)
 - [Avoid write skew](/write_skew_example.py) example
 - [Optimistic and pessimistic transaction](/txn_example.py) example
 
-## Dependcies
+## Prerequisites
 
-- [TiDB](https://docs.pingcap.com/tidb/stable)
-- [mycli](https://www.mycli.net/)
-- [Python 3.6+](https://www.python.org/)
+- Python installed (recommended version 3.10 and above).
+- Start your TiDB cluster. If you don't have a TiDB cluster yet:
 
-## Run
+  - We recommend referring to the document [Create a TiDB Serverless Cluster](https://docs.pingcap.com/tidb/stable/dev-guide-build-cluster-in-cloud) to create your own TiDB Cloud cluster.
+  - Alternatively, you can refer to the documents [Deploy a Local Testing TiDB Cluster](https://docs.pingcap.com/tidb/stable/quick-start-with-tidb) or [Deploy a Formal TiDB Cluster](https://docs.pingcap.com/tidb/stable/production-deployment-using-tiup) to create a local cluster.
 
-### Run the Whole ORM and Driver Test
+- Get the code and install the dependencies
 
-```bash
-make test
-```
+  ```bash
+  git clone https://github.com/pingcap-inc/tidb-example-python.git
+  cd tidb-example-python
+  pip install -r requirement.txt
+  ```
 
-### Run the particular test
+- Configure the `.env` file in the code directory correctly. You can use `cp .env.example .env` to copy the initial configuration file and make changes accordingly. If you are unsure how to obtain this information, please refer to the documents [Obtain the connection parameters](https://docs.pingcap.com/tidbcloud/connect-via-standard-connection-serverless#obtain-the-connection-parameters) and [Where is the CA root path on my system?](https://docs.pingcap.com/tidbcloud/secure-connections-to-serverless-tier-clusters#where-is-the-ca-root-path-on-my-system):
 
-Using run the `peewee_example.py` script as an example:
+  ```properties
+  # TiDB cluster address
+  TIDB_HOST='xxxxxxxx.aws.tidbcloud.com'
+  # TiDB cluster port
+  TIDB_PORT='4000'
+  # TiDB cluster username
+  TIDB_USER='xxxxxxxxxxx.root'
+  # TiDB cluster password
+  TIDB_PASSWORD='xxxxxxx'
+  # The database name to be used for this example
+  TIDB_DB_NAME='test'
+  # The location of the CA certificate on the instance where the example is run. Required when the used cluster require secure connection
+  CA_PATH='/etc/ssl/cert.pem'
+  ```
 
-1. Install dependcy.
+## Run
 
-    ```bash
-    pip install -r requirement.txt
-    ```
+### Run the Entire ORM / Driver Test
+
+```bash
+make test
+```
 
-2. Initial the table.
+### Run a specific test individually
 
-    ```bash
-    mycli --host 127.0.0.1 --port 4000 -u root --no-warn < player_init.sql
-    ```
+Taking **peewee_example.py** as an example: `python3 peewee_example.py`.
 
-3. Run the script.
+### Expected output
 
-    ```bash
-    python3 peewee_example.py
-    ```
\ No newline at end of file
+[Expected output](/Expected-Output.md)
diff --git a/batch_delete.py b/batch_delete.py
index 7e6db01..d06266f 100644
--- a/batch_delete.py
+++ b/batch_delete.py
@@ -12,20 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import MySQLdb
 import datetime
 import time
+from connect_tidb import get_mysqlclient_connection
 
-connection = MySQLdb.connect(
-    host="127.0.0.1",
-    port=4000,
-    user="root",
-    password="",
-    database="bookshop",
-    autocommit=True
-)
-
-with connection:
+with get_mysqlclient_connection() as connection:
     with connection.cursor() as cursor:
         start_time = datetime.datetime(2022, 4, 15)
         end_time = datetime.datetime(2022, 4, 15, 0, 15)
diff --git a/batch_update.py b/batch_update.py
index adf4e18..65c19e9 100644
--- a/batch_update.py
+++ b/batch_update.py
@@ -11,18 +11,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import MySQLdb
 import time
-
-connection = MySQLdb.connect(
-    host="127.0.0.1",
-    port=4000,
-    user="root",
-    password="",
-    database="bookshop",
-    autocommit=True
-)
-
+from connect_tidb import get_mysqlclient_connection
 
 def update_batch(cur, last_book_id: int = None, last_user_id: int = None) -> (int, int):
     if last_book_id is None or last_user_id is None:
@@ -49,7 +39,7 @@ def update_batch(cur, last_book_id: int = None, last_user_id: int = None) -> (in
     return latest_book_id, latest_user_id
 
 
-with connection:
+with get_mysqlclient_connection() as connection:
     with connection.cursor() as cursor:
         # add a column `ten_point`
         # cursor.execute("ALTER TABLE `bookshop`.`ratings` ADD COLUMN `ten_point` BOOL NOT NULL DEFAULT FALSE")
diff --git a/connect_tidb.py b/connect_tidb.py
new file mode 100644
index 0000000..1a8194f
--- /dev/null
+++ b/connect_tidb.py
@@ -0,0 +1,127 @@
+# Copyright 2022 PingCAP, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import os
+from dotenv import load_dotenv
+
+import MySQLdb
+import mysql.connector
+import playhouse.db_url
+import peewee
+import pymysql
+from pymysql.cursors import DictCursor as PyMySQLDictCursor
+import sqlalchemy
+
+class Config:
+    def __init__(self):
+        load_dotenv()
+        self.tidb_host = os.getenv("TIDB_HOST", "127.0.0.1")
+        self.tidb_port = int(os.getenv("TIDB_PORT", "4000"))
+        self.tidb_user = os.getenv("TIDB_USER", "root")
+        self.tidb_password = os.getenv("TIDB_PASSWORD", "")
+        self.tidb_db_name = os.getenv("TIDB_DB_NAME", "test")
+        self.ca_path = os.getenv("CA_PATH", "")
+
+def get_mysqlclient_connection(autocommit:bool=True) -> MySQLdb.Connection:
+    config = Config()
+    db_conf = {
+        "host": config.tidb_host,
+        "port": config.tidb_port,
+        "user": config.tidb_user,
+        "password": config.tidb_password,
+        "database": config.tidb_db_name,
+        "autocommit": autocommit
+    }
+
+    if config.ca_path:
+        db_conf["ssl_mode"] = "VERIFY_IDENTITY"
+        db_conf["ssl"] = {"ca": config.ca_path}
+
+    return MySQLdb.connect(**db_conf)
+
+
+def get_mysql_connector_python_connection(autocommit:bool=True) -> mysql.connector.MySQLConnection:
+    config = Config()
+    db_conf = {
+        "host": config.tidb_host,
+        "port": config.tidb_port,
+        "user": config.tidb_user,
+        "password": config.tidb_password,
+        "database": config.tidb_db_name,
+        "autocommit": autocommit
+    }
+
+    if config.ca_path:
+        db_conf["ssl_verify_identity"] = True
+        db_conf["ssl_ca"] = config.ca_path
+
+    return mysql.connector.connect(**db_conf)
+
+
+def get_pymysql_connection(autocommit: bool = False) -> pymysql.Connection:
+    config = Config()
+    db_conf = {
+        "host": config.tidb_host,
+        "port": config.tidb_port,
+        "user": config.tidb_user,
+        "password": config.tidb_password,
+        "database": config.tidb_db_name,
+        "autocommit": autocommit,
+        "cursorclass": PyMySQLDictCursor,
+    }
+
+    if config.ca_path:
+        db_conf["ssl_verify_cert"] = True
+        db_conf["ssl_verify_identity"] = True
+        db_conf["ssl_ca"] = config.ca_path
+
+    return pymysql.connect(**db_conf)
+
+
+def get_peewee_db() -> peewee.MySQLDatabase:
+    config = Config()
+    url = f'mysql://{config.tidb_user}:{config.tidb_password}@{config.tidb_host}:{config.tidb_port}/{config.tidb_db_name}'
+    if config.ca_path:
+        return playhouse.db_url.connect(url, ssl_verify_cert=True, ssl_ca=config.ca_path)
+    else:
+        return playhouse.db_url.connect(url)
+
+
+def get_sqlalchemy_engine():
+    config = Config()
+    url = f'mysql://{config.tidb_user}:{config.tidb_password}@{config.tidb_host}:{config.tidb_port}/{config.tidb_db_name}'
+    if config.ca_path:
+        return sqlalchemy.create_engine(url, connect_args={
+            "ssl_mode": "VERIFY_IDENTITY",
+            "ssl": { "ca": config.ca_path }
+        })
+    else:
+        return sqlalchemy.create_engine(url)
+
+
+def __recreate_table(connection) -> None:
+    with connection.cursor() as cur:
+        cur.execute("DROP TABLE IF EXISTS player;")
+        cur.execute("CREATE TABLE player (`id` VARCHAR(36), `coins` INTEGER, `goods` INTEGER, PRIMARY KEY (`id`));")
+
+def mysqlclient_recreate_table() -> None:
+    __recreate_table(get_mysqlclient_connection(autocommit=True))
+
+
+def mysql_connector_python_recreate_table() -> None:
+    __recreate_table(get_mysql_connector_python_connection(autocommit=True))
+
+
+def pymysql_recreate_table() -> None:
+    __recreate_table(get_pymysql_connection(autocommit=True))
+
diff --git a/mysql_connector_python_example.py b/mysql_connector_python_example.py
index a91458c..3f16e46 100644
--- a/mysql_connector_python_example.py
+++ b/mysql_connector_python_example.py
@@ -13,22 +13,14 @@
 # limitations under the License.
 
 import uuid
+from connect_tidb import get_mysql_connector_python_connection, mysql_connector_python_recreate_table
+
 from typing import List
 
-from mysql.connector import connect, MySQLConnection
+from mysql.connector import MySQLConnection
 from mysql.connector.cursor import MySQLCursor
 
 
-def get_connection(autocommit: bool = True) -> MySQLConnection:
-    connection = connect(host='127.0.0.1',
-                         port=4000,
-                         user='root',
-                         password='',
-                         database='test')
-    connection.autocommit = autocommit
-    return connection
-
-
 def create_player(cursor: MySQLCursor, player: tuple) -> None:
     cursor.execute("INSERT INTO player (id, coins, goods) VALUES (%s, %s, %s)", player)
 
@@ -104,7 +96,7 @@ def trade(connection: MySQLConnection, sell_id: str, buy_id: str, amount: int, p
 
 
 def simple_example() -> None:
-    with get_connection(autocommit=True) as connection:
+    with get_mysql_connector_python_connection(autocommit=True) as connection:
         with connection.cursor() as cur:
             # create a player, who has a coin and a goods.
             create_player(cur, ("test", 1, 1))
@@ -133,7 +125,7 @@ def simple_example() -> None:
 
 
 def trade_example() -> None:
-    with get_connection(autocommit=False) as conn:
+    with get_mysql_connector_python_connection(autocommit=False) as conn:
         with conn.cursor() as cur:
             # create two players
             # player 1: id is "1", has only 100 coins.
@@ -159,5 +151,6 @@ def trade_example() -> None:
             print(f'id:2, coins:{player2_coin}, goods:{player2_goods}')
 
 
+mysql_connector_python_recreate_table()
 simple_example()
 trade_example()
diff --git a/mysqlclient_example.py b/mysqlclient_example.py
index 92905c8..ba41e73 100644
--- a/mysqlclient_example.py
+++ b/mysqlclient_example.py
@@ -15,26 +15,15 @@
 import uuid
 from typing import List
 
-import MySQLdb
 from MySQLdb import Connection
 from MySQLdb.cursors import Cursor
+from connect_tidb import get_mysqlclient_connection, mysqlclient_recreate_table
 
 # If you don't have a TiDB cluster, just register here:
 # https://tidbcloud.com/console/clusters/create-cluster
 # And get a TiDB Cloud Serverless Tier in 1 min (no kidding, and it's free now)
 
 
-def get_connection(autocommit: bool = True) -> MySQLdb.Connection:
-    return MySQLdb.connect(
-        host="127.0.0.1",
-        port=4000,
-        user="root",
-        password="",
-        database="test",
-        autocommit=autocommit
-    )
-
-
 def create_player(cursor: Cursor, player: tuple) -> None:
     cursor.execute("INSERT INTO player (id, coins, goods) VALUES (%s, %s, %s)", player)
 
@@ -110,7 +99,7 @@ def trade(connection: Connection, sell_id: str, buy_id: str, amount: int, price:
 
 
 def simple_example() -> None:
-    with get_connection(autocommit=True) as conn:
+    with get_mysqlclient_connection(autocommit=True) as conn:
         with conn.cursor() as cur:
             # create a player, who has a coin and a goods.
             create_player(cur, ("test", 1, 1))
@@ -137,7 +126,7 @@ def simple_example() -> None:
 
 
 def trade_example() -> None:
-    with get_connection(autocommit=False) as conn:
+    with get_mysqlclient_connection(autocommit=False) as conn:
         with conn.cursor() as cur:
             # create two players
             # player 1: id is "1", has only 100 coins.
@@ -163,5 +152,6 @@ def trade_example() -> None:
             print(f'id:2, coins:{player2_coin}, goods:{player2_goods}')
 
 
+mysqlclient_recreate_table()
 simple_example()
 trade_example()
diff --git a/peewee_example.py b/peewee_example.py
index 9eaf5c0..58098a5 100644
--- a/peewee_example.py
+++ b/peewee_example.py
@@ -11,16 +11,14 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import os
 import uuid
 from typing import List
 
 from peewee import *
 
-from playhouse.db_url import connect
-
-db = connect('mysql://root:@127.0.0.1:4000/test')
+from connect_tidb import get_peewee_db
 
+db = get_peewee_db()
 
 class Player(Model):
     id = CharField(max_length=36, primary_key=True)
diff --git a/player_init.sql b/player_init.sql
deleted file mode 100644
index 5b8eead..0000000
--- a/player_init.sql
+++ /dev/null
@@ -1,9 +0,0 @@
-USE test;
-DROP TABLE IF EXISTS player;
-
-CREATE TABLE player (
-    `id` VARCHAR(36),
-    `coins` INTEGER,
-    `goods` INTEGER,
-    PRIMARY KEY (`id`)
-);
\ No newline at end of file
diff --git a/pymysql_example.py b/pymysql_example.py
index 210d9d0..d574691 100644
--- a/pymysql_example.py
+++ b/pymysql_example.py
@@ -14,20 +14,9 @@
 import uuid
 from typing import List
 
-import pymysql.cursors
 from pymysql import Connection
 from pymysql.cursors import DictCursor
-
-
-def get_connection(autocommit: bool = False) -> Connection:
-    return pymysql.connect(host='127.0.0.1',
-                           port=4000,
-                           user='root',
-                           password='',
-                           database='test',
-                           cursorclass=DictCursor,
-                           autocommit=autocommit)
-
+from connect_tidb import get_pymysql_connection, pymysql_recreate_table
 
 def create_player(cursor: DictCursor, player: tuple) -> None:
     cursor.execute("INSERT INTO player (id, coins, goods) VALUES (%s, %s, %s)", player)
@@ -104,7 +93,7 @@ def trade(connection: Connection, sell_id: str, buy_id: str, amount: int, price:
 
 
 def simple_example() -> None:
-    with get_connection(autocommit=True) as connection:
+    with get_pymysql_connection(autocommit=True) as connection:
         with connection.cursor() as cur:
             # create a player, who has a coin and a goods.
             create_player(cur, ("test", 1, 1))
@@ -131,7 +120,7 @@ def simple_example() -> None:
 
 
 def trade_example() -> None:
-    with get_connection(autocommit=False) as connection:
+    with get_pymysql_connection(autocommit=False) as connection:
         with connection.cursor() as cur:
             # create two players
             # player 1: id is "1", has only 100 coins.
@@ -155,5 +144,6 @@ def trade_example() -> None:
             print(get_player(cur, "2"))
 
 
+pymysql_recreate_table()
 simple_example()
 trade_example()
\ No newline at end of file
diff --git a/requirement.txt b/requirement.txt
index b22a635..2219862 100644
--- a/requirement.txt
+++ b/requirement.txt
@@ -8,6 +8,7 @@ mysqlclient==2.1.1
 peewee==3.15.4
 protobuf==3.20.1
 PyMySQL==1.0.2
+python-dotenv==1.0.0
 pytz==2022.6
 SQLAlchemy==1.4.44
 sqlparse==0.4.3
diff --git a/sqlalchemy_example.py b/sqlalchemy_example.py
index f9a9d03..a2e41fe 100644
--- a/sqlalchemy_example.py
+++ b/sqlalchemy_example.py
@@ -15,12 +15,12 @@
 import uuid
 from typing import List
 
-from sqlalchemy import create_engine, String, Column, Integer, select, func
+from sqlalchemy import String, Column, Integer, select, func
 from sqlalchemy.orm import declarative_base, sessionmaker
+from connect_tidb import get_sqlalchemy_engine
 
-engine = create_engine('mysql://root:@127.0.0.1:4000/test')
+engine = get_sqlalchemy_engine()
 Base = declarative_base()
-Base.metadata.create_all(engine)
 Session = sessionmaker(bind=engine)
 
 
@@ -127,5 +127,7 @@ def trade_example() -> None:
         session.commit()
 
 
+Base.metadata.drop_all(engine)
+Base.metadata.create_all(engine)
 simple_example()
 trade_example()
diff --git a/txn_example.py b/txn_example.py
index 736ef5c..5681a68 100644
--- a/txn_example.py
+++ b/txn_example.py
@@ -17,6 +17,7 @@
 import os
 import datetime
 from threading import Thread
+from connect_tidb import get_mysqlclient_connection
 
 REPEATABLE_ERROR_CODE_SET = {
     9007,  # Transactions in TiKV encounter write conflicts.
@@ -26,19 +27,8 @@
 }
 
 
-def create_connection():
-    return MySQLdb.connect(
-        host="127.0.0.1",
-        port=4000,
-        user="root",
-        password="",
-        database="bookshop",
-        autocommit=False
-    )
-
-
 def prepare_data() -> None:
-    connection = create_connection()
+    connection = get_mysqlclient_connection(autocommit=False)
     with connection:
         with connection.cursor() as cursor:
             cursor.execute("INSERT INTO `books` (`id`, `title`, `type`, `published_at`, `price`, `stock`) "
@@ -53,7 +43,7 @@ def prepare_data() -> None:
 
 def buy_optimistic(thread_id: int, order_id: int, book_id: int, user_id: int, amount: int,
                    optimistic_retry_times: int = 5) -> None:
-    connection = create_connection()
+    connection = get_mysqlclient_connection(autocommit=False)
 
     txn_log_header = f"/* txn {thread_id} */"
     if thread_id != 1:
@@ -112,7 +102,7 @@ def buy_optimistic(thread_id: int, order_id: int, book_id: int, user_id: int, am
 
 
 def buy_pessimistic(thread_id: int, order_id: int, book_id: int, user_id: int, amount: int) -> None:
-    connection = create_connection()
+    connection = get_mysqlclient_connection(autocommit=False)
 
     txn_log_header = f"/* txn {thread_id} */"
     if thread_id != 1:
diff --git a/write_skew_example.py b/write_skew_example.py
index 489fc4c..71986ce 100644
--- a/write_skew_example.py
+++ b/write_skew_example.py
@@ -13,22 +13,11 @@
 # limitations under the License.
 from threading import Thread, Semaphore
 
-import MySQLdb
-
-
-def create_connection(autocommit=True):
-    return MySQLdb.connect(
-        host="127.0.0.1",
-        port=4000,
-        user="root",
-        password="",
-        database="test",
-        autocommit=autocommit
-    )
+from connect_tidb import get_mysqlclient_connection
 
 
 def prepare_data() -> None:
-    connection = create_connection(autocommit=True)
+    connection = get_mysqlclient_connection(autocommit=True)
     with connection:
         with connection.cursor() as cursor:
             # create table
@@ -48,7 +37,7 @@ def prepare_data() -> None:
 
 
 def ask_for_leave(thread_id: int, txn1_run: Semaphore, doctor_id: int) -> None:
-    connection = create_connection(False)
+    connection = get_mysqlclient_connection(autocommit=False)
     txn_log_header = f"/* txn {thread_id} */"
     if thread_id != 1:
         txn_log_header = "\t" + txn_log_header