执行代码后，数据库里sal没变化

代码执行后提示：

Not all parameters were used in the SQL statement

Process finished with exit code 0

代码如下：

import mysql.connector.pooling
config = {
       'host': 'localhost',
       'port': 3306,
       'user': 'root',
       'password': '123456',
       'database': 'demo'
}
try:
   pool = mysql.connector.pooling.MySQLConnectionPool(
       **config,
       pool_size=10
   )
   con = pool.get_connection()
   con.start_transaction()
   cursor = con.cursor()
   sql = 'UPDATE t_emp SET sal=sal+s% WHERE deptno=s% '
   cursor.execute(sql, (200,20))
   con.commit()
except Exception as e:
   if 'con' in dir():
       con.rollback()
   print(e)