如果值达到800，如何创建MySQL函数来更新数据库？

Question

我试图让数据库每秒检查一次表，看看XP值是否达到800，如果达到，则将rank值设置为“Elite Genin”并将XP值设置为0。

@bot.event
async def on_message(message):
    guild = message.guild.id
    table = "PEOPLE_" + str(guild)

    try:
        connection = mysql.connector.connect(
        host="localhost",
        port="3306",
        user="root",
        password="root",
        database="naruto_game"
        )
        cursor = connection.cursor()

        sql_event_query = """CREATE EVENT geninpromotion
                             ON SCHEDULE EVERY 1 Second
                             STARTS CURRENT_TIMESTAMP + INTERVAL 1 Second 
                             ENDS CURRENT_TIMESTAMP + INTERVAL 24 Hours 
                             DO UPDATE """ + table + """ SET rank = 'Elite Genin' where xp = 800 AND SET xp = 0"""
        cursor.execute(sql_event_query)

    except mysql.connector.Error as error:
        print("Failed to find name: {}".format(error))
    finally:
        if connection.is_connected():
            cursor.close()
            connection.close()
            print("MySQL connection has been closed.")
    print("Event created.")

但是当我运行后发送消息时，出现此错误。

Failed to find name: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'Hours DO UPDATE " + table + " SET rank = 'Elite Genin' where xp = 800 AND SET xp' at line 2

Answer 1

我看到三个语法错误。

1. 您想要的时间间隔关键字是

   HOUR

   ，而不是

   HOURS

   。有关时间间隔语法的详细信息，请阅读 https://dev.mysql.com/doc/refman/8.4/en/expressions.html#temporal-intervals。

2. 命名列时要小心

   rank

   ，因为这是 MySQL 中的保留关键字。请参阅https://stackoverflow.com/a/23446378/20860

3. 如果要在

   UPDATE

   语句中设置两列，请将它们设置在

   WHERE

   子句之前。

固定的SQL语法应该如下：

CREATE EVENT geninpromotion
 ON SCHEDULE EVERY 1 Second
 STARTS CURRENT_TIMESTAMP + INTERVAL 1 SECOND 
 ENDS CURRENT_TIMESTAMP + INTERVAL 24 HOUR
 DO UPDATE mytable SET `rank` = 'Elite Genin', xp = 0 WHERE xp >= 800

注意修复：

• 使用了

  HOUR

  关键字。
• 用反引号分隔

  rank

  ，以防止其被解释为关键字。
• 重新排序了

  UPDATE

  语句中的分配。