flask连接mysql数据库

要使用Flask连接MySQL数据库，需要遵循以下步骤：

1. 安装MySQL驱动程序：可以使用PyMySQL，mysql-connector-python等。

2. 在Flask应用程序中导入MySQL驱动程序和Flask库

import MySQLdb
from flask import Flask

3. 在Flask应用程序中配置MySQL连接参数，例如：

app = Flask(__name__)
app.config['MYSQL_HOST'] = 'localhost'  # MySQL服务器地址
app.config['MYSQL_USER'] = 'root'  # MySQL用户名
app.config['MYSQL_PASSWORD'] = 'password'  # MySQL密码
app.config['MYSQL_DB'] = 'database_name'  # MySQL数据库名

4. 创建MySQL连接并获取游标对象

mysql = MySQLdb.connect(host=app.config['MYSQL_HOST'], user=app.config['MYSQL_USER'],
                        passwd=app.config['MYSQL_PASSWORD'], db=app.config['MYSQL_DB'])
cursor = mysql.cursor()

5. 执行SQL查询语句并处理结果

query = "SELECT * FROM table_name"
cursor.execute(query)
results = cursor.fetchall()
for row in results:
    print(row)

6. 关闭MySQL连接

mysql.close()

完整代码示例：

import MySQLdb
from flask import Flask

app = Flask(__name__)
app.config['MYSQL_HOST'] = 'localhost'
app.config['MYSQL_USER'] = 'root'
app.config['MYSQL_PASSWORD'] = 'password'
app.config['MYSQL_DB'] = 'database_name'

mysql = MySQLdb.connect(host=app.config['MYSQL_HOST'], user=app.config['MYSQL_USER'],
                        passwd=app.config['MYSQL_PASSWORD'], db=app.config['MYSQL_DB'])
cursor = mysql.cursor()

@app.route('/')
def index():
    query = "SELECT * FROM table_name"
    cursor.execute(query)
    results = cursor.fetchall()
    for row in results:
        print(row)
    mysql.close()
    return 'Hello World!'

if __name__ == '__main__':
    app.run()