Impossible to merge - Preview not available

[mchacha]

Hi,

I'm trying to merge my main query (which comes from excel source A) to another one (excel source B), but I can't as it says Preview not available. 

I've already merged some info from main query to the other one. Could that be the issue? 

I've tried to update preview, update file, close and open, but still have the same issue. At first it loads, and then there a warning sign next to the other query. 

1.

2.

Could you please help me ? 

Thank you 🙂

[rusgesig]

Same Problem.
Power Query in Excel, the preview for the table I want to merge is blacked out completely - it doesn't even show the columns for me to merge.
This is after pasting the tables as values into a spreadsheet, no connectors or anything.

[PwerQueryKees · Accepted solution]

Without the details of the various queries it is hard to say what is wrong exactly, so I am just guessing here...

BUT:

You mention "DN and invoices table, I merge it with Shared list extraction".
It is causing a dependency because the merge you did earlier now suddenly refers to itself because of the merge you try to do,

You can try to make a new query refering to Shared List Extraction and join that new query with DN and Invoices.

[Anonymous]

Hi @mchacha ,

1. Are there any dependencies between tables? For example, 'DN and Invoices' references 'Shared list extraction', if so, try duplicating a 'Shared list extraction' table (not loaded), then use 'DN and Invoices' to reference data from this duplicate table.

2. Sometimes, simply refreshing the preview can help. You can do this by clicking the refresh button in the Power Query Editor.

3. Go to and clear the Data Management Cache. File -> Options and Settings -> Options -> Data Load. This can sometimes resolve preview issues.

Best Regards,
Gao
Community Support Team

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[mchacha]

Hi, thank you for your reply.

1. In steps from DN and invoices table, I merge it with Shared list extraction one to retrieve some information from the Shared list extraction table (so I guess, it has dependencies). If I duplicate the Shared list extraction table and merge the new one with DN and invoices, then in my report information would be taken from two different tables? 

2. I've done it multiple times but still with the same result. 

3. I've tried it as well and it had no changes. 

Thank you

[Anonymous]

Hi @mchacha ,

-- then in my report information would be taken from two different tables?

Yes. The duplicate creates an exact copy of the original query, including all the steps applied to it. Changes made to the duplicate do not affect the original query, and vice versa. 

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

How to get your questions answered quickly --  How to provide sample data in the Power BI Forum

[mchacha]

The issue is, I've already created many different tabs, visuals and measures from the original one - it wouldn't be a lasting solution to do a copy then merge on the copy. Moreover, I guess it will load it twice and the original won't be useful anymore ? 😞 

The thing is, when I do the opposite (merge from table DN and invoices the table Shared list extraction) it works... 

[Anonymous]

Hi @mchacha ,

The duplicate copy table can be right-clicked and unchecked Enable load, so that it is not loaded into the model, and you can still use the original table with the created visual and measures.

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

How to get your questions answered quickly --  How to provide sample data in the Power BI Forum

[lbendlin]

You need to indicate which column(s) you want to merge the tables on.

Note:  Merging in Power Query is very expensive. Avoid if possible.  Use the data model instead.

[mchacha]

Hey, thanks for your reply. The thing is, even if I select a column in my first table, I'm not able to select a column in the second as it doesn't load. Thank you for the tip, I didn't know. However, I wanted to merge my two tables with my invoice number. As I have more/different invoices in one table compare to the other, I'm afraid I can't use the data model to create relations?