Appending data causing duplication

[raynay]

I am importing three datasets for three years data from SQL server to Power BI desktop. I then append these queries to give me one dataset containing three years' worth of data. The data have consistent columns and a unique ID column. There is no duplication of IDs between datasets nor within individual datasets. However, when I analyse the appended data, there is duplication of some of these IDs. Since this first happened, I have refreshed the data as extra entries have been added to one of the SQL data sources. The duplication still occurs but it is for a different set of IDs. In the Power BI file where this happens, I also have a number of other data sources imported. I have tried to recreate the issue in a new file - when I just imported the three sources in question and appended there was no duplication. Do you have any explanation for this issue?

[v-haibl-msft]

@raynay

I didn’t encounter and could not repro the same issue. Are you using the latest Feb 2017 version of Power BI Desktop? If there is no duplication in the new file, can you use it instead of the old one?

Best Regards,

Herbert

[raynay]

Thanks for your reply @v-haibl-msft

I'm currently using the January version as our enterprise IT team haven't got as far as deploying the February one.

I could use the other file (and I do intend to if there's no better solution) but:

a) This involves a moderate amount of work to configure it as I have another dozen data sources to load, set up relationships, recreate measures etc.

b) I would really like to know why this happened so I can be confident it won't happen again. My data refresh weekly and it would be a problem if this error returned at a later week once everything is deployed.

[v-haibl-msft]

@raynay

For item a, you can try with Power BI Template.

For item b, since I have not seen such problem and cannot repro locally. I suggest you to create a support ticket at http://support.powerbi.com (see bottom of page).

Best Regards,

Herbert