There is already an open DataReader associated with this Command which must be closed first
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",
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