关于多线程访问ExecuteScalar,ExecuteNonQuery
多线程访问ExecuteScalar,ExecuteNonQuery时报:
System.InvalidOperationException: ExecuteScalar 需要打开的并且可用的连接。该连接的当前状态是 Open, Executing。
at System.Data.OleDb.OleDbConnection.SetStateExecuting(OleDbCommand attempt, String method, Boolean flag)
at System.Data.OleDb.OleDbCommand.ValidateConnectionAndTransaction(String method, Int32& localState)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteScalar()
是怎么回事阿 ?