通常出现在嵌套查询数据库(比如在一个qry的遍历时,又进行了数据库查询)

通过在连接字符串中允许MARS可以轻松解决这个问题。 将MultipleActiveResultSets = true添加到连接字符串的提供程序部分

    "SqlServerConnection": "Server=.\\sqlexpress;Database=test;Integrated Security=True;Connect Timeout=15;MultipleActiveResultSets=true",

　　

There is already an open DataReader associated with this Command which must be closed first的更多相关文章

  1. There is already an open DataReader associated with this Command which must be closed first." exception in Entity Framework

    Fixing the "There is already an open DataReader associated with this Command which must be clos ...

  2. 在实体对象中访问导航属性里的属性值出现异常“There is already an open DataReader associated with this Command which must be closed first”

    在实体对象中访问导航属性里的属性值出现异常“There is already an open DataReader associated with this Command which must be ...

  3. 关于MultipleActiveResultSets属性导致的There is already an open DataReader associated with this Command which must be closed first的解决方法

    执行SqlDataReader.Read之后,如果还想用另一个SqlCommand执行Insert或者Update操作的话,会得到一个错误提示:There is already an open Dat ...

  4. 多线程下，多次操作数据库报错，There is already an open DataReader associated with this Command which must be closed first.

    原文:https://www.cnblogs.com/sdusrz/p/4433108.html 执行SqlDataReader.Read之后,如果还想用另一个SqlCommand执行Insert或者 ...

  5. error 'there is already an open datareader associated with this command which must be closed first'

    This can be easily solved by allowing MARS in your connection string. Add MultipleActiveResultSets=t ...

  6. There is already an open DataReader associated with this Connection which must be closed first

    使用MVC4 EF Linq获取foreach列表循环的时候遇到了如下的问题:报错提示 There is already an open DataReader associated with this ...

  7. C#.net mysql There is already an open datareader associated with this command引发的问题

    [参考]There is already an open datareader associated with this command引发的问题 我在语句中并未使用 DataReader,未何也提示 ...

  8. EF There is already an open DataReader associated with this Command

    捕捉到 System.InvalidOperationException _HResult=-2146233079 _message=意外的连接状态.在使用包装提供程序时,请确保在已包装的 DbCon ...

  9. There is already an open DataReader associated with this Connection which must be closed first EF

    废话不多说,直接 上图,及解决办法.不过问题还不是太清楚到底为什么会出现这个情况..........  

随机推荐

  1. centos虚拟机 与主机同步时间

    同步系统时间: yum install ntp ntpdate cn.pool.ntp.org ntpdate 0.centos.pool.ntp.org rm /etc/localtime ln - ...

  2. Java8——Optional

    /* * 一.Optional 容器类:用于尽量避免空指针异常 * Optional.of(T t) : 创建一个 Optional 实例 * Optional.empty() : 创建一个空的 Op ...

  3. luoguP3455 [POI2007]ZAP-Queries

    题意 设\(f(n)=\sum\limits_{i=1}^{a}\sum\limits_{j=1}^{b}[gcd(i,j)==n],F(n)=\sum\limits_{n|d}f(d)\) 发现\( ...

  4. Genome Sequencing of MuseumSpecimens Reveals Rapid Changes in the Genetic Composition of Honey Bees in California

    文章地址:https://academic.oup.com/gbe/article/10/2/458/4810442#supplementary-data Abstract 在自然生态系统和管理生态系 ...

  5. Graphviz学习

    (入门教程)[https://www.luogu.com.cn/blog/umr/graphviz]

  6. [LeetCode] 264. Ugly Number II 丑陋数之二

    Write a program to find the n-th ugly number. Ugly numbers are positive numbers whose prime factors ...

  7. scss 入门基础

    在一个项目中,样式是必不可少的一部分,而对于一个完整的项目来说是有个基准色调的.在项目需求变化不大的情况下,可以直接在css中写这些颜色值之类的东西.但是如果遇到一个朝令夕改的领导或者甲方,那会变得相 ...

  8. centos7.5安装java JDK、tomcat、mysql

    参考资料: https://www.cnblogs.com/sxdcgaq8080/p/7492426.html https://blog.csdn.net/ds986619036/article/d ...

  9. JavaScript 系列--JavaScript一些奇淫技巧的实现方法（二）数字格式化 1234567890转1,234,567,890；argruments 对象(类数组)转换成数组

    一.前言 之前写了一篇文章:JavaScript 系列--JavaScript一些奇淫技巧的实现方法(一)简短的sleep函数,获取时间戳 https://www.mwcxs.top/page/746 ...

  10. 在Azure DevOps Server（TFS）上集成Python环境，实现持续集成和发布

    Python和Azure DevOps Server Python是一种计算机程序设计语言.是一种动态的.面向对象的脚本语言,最初主要为系统运维人员编写自动化脚本,在实际应用中,Python已经在前端 ...