使用pymysql遇到报错：An error occurred: execute() first

TerminatorRoot

于 2024-07-12 11:58:53 发布

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文章标签：数据库 python

本文链接：https://blog.youkuaiyun.com/TerminatorRoot/article/details/140375468

原始文本如下：

 try:
	 with connection.cursor() as cursor:
	      # SQL查询语句
	      # 根据 last_id 构建SQL查询语句  
	      if last_id == 0:  
	          # 如果没有读取过数据，从第一条开始  
	          # print(last_id)
	          sql = "SELECT * FROM phrase01 ORDER BY id ASC LIMIT 1"  
	          
	      else:  
	          # 否则，从上次读取的ID的下一行开始  
	          sql = "SELECT * FROM phrase01 WHERE id > %s ORDER BY id ASC LIMIT 1"  
	          cursor.execute(sql, (last_id,))

运行后会报错：
An error occurred: execute() first
参考https://blog.youkuaiyun.com/itguangzhi/article/details/82381743这篇文章，在第一个sql语句下面补充了内容，解决该问题，以下是修改后代码：

try:
    with connection.cursor() as cursor:
        # SQL查询语句
        # 根据 last_id 构建SQL查询语句 
        if last_id == 0:  
            # 如果没有读取过数据，从第一条开始  
            # print(last_id)
            sql = "SELECT * FROM phrase01 ORDER BY id ASC LIMIT 1"  
            cursor.execute(sql)#注意这句必须要有，否则会报错：An error occurred: execute() first
        else:  
            # 否则，从上次读取的ID的下一行开始  
            sql = "SELECT * FROM phrase01 WHERE id > %s ORDER BY id ASC LIMIT 1"  
            cursor.execute(sql, (last_id,))