python3删除Mysql空数据

python中用None表示空，但是在查询Mysql数据中，参数不能传None

例如

def select_word1():
    db = MysqlConn()
    cursor = db.cursor()
    sql = 'select * from HotWord where detail=%s'
    try:
        cursor.execute(sql,None)
        row = cursor.fetchone()
        print(row)
    except:
        traceback.print_exc()
        print('查询失败')
        db.rollback()
    db.close()


if __name__ == '__main__':
    select_word1()

会报错

pymysql.err.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax

正确用法

def delete_None_detail():
    db = MysqlConn()
    cursor = db.cursor()
    sql = 'delete from HotWord where detail is null'
    try:
        cursor.execute(sql)
        db.commit()
        print('删除成功')
    except:
        traceback.print_exc()
        print('删除失败')
        db.rollback()
    db.close()

Mysql中用 is null表示空