Question: I am trying to replicate the example of [this](http://blaze.pydata.org/blog/2015/09/08/reddit-comments/) page about castra, dask and reddit comments, and I get the above error when I run the 

> 
> dd.from\_castra(data,columns)
> 
> 
> 

My castra file took some hours to be created but it is clean and exactly as the tutorial mentions.

Used both my macbook and an Ubuntu instance on amazon AWS and had the same issue.

Same code and file works fine in a windows PC.

Any info could be helpful!

> 
> ValueError: Expected iterable of tuples of (name, dtype), got ['archived', 'author',....]
> 
> 
>

Answer: 
What don't you understand about the message? You have an aggregation query with no `GROUP BY`. Hence, *all* columns must be the arguments to aggregation functions.

I suspect that you intend:

```
SELECT @Total = CAST(SUM(WorkedTimeInMinutes * KayakoValue) AS FLOAT)/60
FROM [VDBSERVER2012\SQLEXPRESS2014].PlaterITDB.dbo.KayakoTimeEntries kte INNER JOIN
     ClientContract cc
     ON ClientId = @ClientId AND
        Workdate BETWEEN cc.StartDt AND cc.EndDt
WHERE OrganizationID = @KKId AND
      WorkDate BETWEEN @StartDate AND @EndDate AND MONTH(WorkDate) = @Month

```

Note that you should learn to use table aliases and to qualify all column names. This is a good practice for writing readable and maintainable code.
You should use 'KayakoValue' in aggregate function like sum,count, . . . or in group by at the end .

`SELECT @Total = ((CAST(SUM(WorkedTimeInMinutes) AS FLOAT)/60) * KayakoValue)
FROM [VDBSERVER2012\SQLEXPRESS2014].PlaterITDB.dbo.KayakoTimeEntries
INNER JOIN ClientContract ON ClientId = @ClientId AND Workdate BETWEEN ClientContract.StartDt AND ClientContract.EndDt
WHERE OrganizationID = @KKId AND WorkDate BETWEEN @StartDate AND @EndDate AND MONTH(WorkDate) = @Month
group by KayakoValue`

OR 

`SELECT @Total = ((CAST(SUM(WorkedTimeInMinutes * KayakoValue) AS FLOAT)/60))
FROM [VDBSERVER2012\SQLEXPRESS2014].PlaterITDB.dbo.KayakoTimeEntries
INNER JOIN ClientContract ON ClientId = @ClientId AND Workdate BETWEEN ClientContract.StartDt AND ClientContract.EndDt
WHERE OrganizationID = @KKId AND WorkDate BETWEEN @StartDate AND @EndDate AND MONTH(WorkDate) = @Month`