Data extraction "data column in the external data does not contain unique value"

[dans557JT]

Hello all,

I am extracting attribute data from blocks through the data extraction tool. However, I am running into a problem on step 4. I am wanting to link external data to a spreadsheet. I data linked the spreadsheet, and go up to the point of data matching. However, no matter what I do, I get the following error:

"the data column in the external data does not contain unique values"

I have no idea what this means. The only forums online pertaining to this issue are from 2007 and they are extremely vague and unhelpful. Does anyone know what I am doing wrong? I have attached the, the drawing file, and the spreadsheet file. Of course it is just my luck, that the autodesk forum won't let me upload the data extraction file. If anyone can help, I will email it to you. 

Thank you!

[cadffm]

Not tested your files, but hope this explain and helps
https://forums.autodesk.com/t5/autocad-forum/external-data-does-not-contain-unique-values/td-p/21959...

Try it without special characters in Title row

No * (and no / of course)

[dans557JT]

I removed the special characters and it still wont link. I clicked the hyperlink that you provided and tried the work around that was offered and even that did not work.

I am at a total loss. As a matter of fact, I have never been able to get the link to work under any circumstances. I wish that AutoCAD had a guide on how to use this function in detail. Every forum just says "yeah the error means just as it says" but I don't seem to be the only one confused by the wording. 

[TheCADnoob]

What is your end goal? It seems that you have already linked your table to your drawing. 

[dans557JT]

It is my understanding that if you "link to external data" then the data extraction table will write to the existing excel file without creating a new one each time. If this is not the function, then can someone explain to me what the purpose of linking external data is?

[TheCADnoob]

If you use DATALINKUPDATE you can upload to source and download from source once the table is linked.

I have never used the feature in dataextraction as you are describing. Its my vague understanding that that is used to amend an existing extraction with and exiting spread sheet data. 

[john.vellek]

Hi @dans557JT,

I battled this type of issue a couple of weeks ago. I found that a dataextraction works great to insert a table in the drawing file, can export to an external file.  Datalink works great to insert a table in to the drawing and is bidirectional. I did find however, that trying to connect the datalink to a data extraction does not work well. I have logged this with the QA team for more research but at this point in time I would avoid this step in your process.

If you want this to work partway, you will need to decide if it is more important to manipulate the data in an External file and then reinsert a table in AutoCAD or to have the dataextraction in AutoCAD update easily and then export the data to the external file from this table.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[cadffm]

"It is my understanding that if you "link to external data" then the data extraction table will write to the existing excel file without creating a new one each time. If this is not the function, then can someone explain to me what the purpose of linking external data is?"

You can modify your dataextract-Result

- hide columns

- sort by..

- modify format of value (example for Textvalue: Alle Values UPPERCASE)

- create additional form columns

- and so on

http://help.autodesk.com/view/ACD/2018/ENU/?guid=GUID-8F587A78-1D60-47F6-8254-A534D68439FF

with [external data link] you can attach additional content from an external datalink(excel) to your dataextract-table or/and excelsheet.

Note: You create a  new Table or ExcelSheet an combine your drawing-extractiopn with data from the external data link.

I google for you because a picture or video says more than..yes.

https://www.youtube.com/watch?v=QLGoxHMg8Zw

[dans557JT]

I have a third party software that can link an excel file to CAD, so I would much rather be able to update an external source file with my extracted data. Can you provide the partway work around? Also, would you happen to have a link to the discussion you had a few weeks back?(If it was on a forum).

[dans557JT]

This part I understand, it just gives me the error every time I try to link to external source which is annoying. I know it must be something I am doing wrong, however, there does not seem to be a step by step instruction for linking to external data. In other words, I am doing it wrong but can't find out how to link to external data the correct way.

[cadffm · Accepted solution]

I think you had not understand.

The external-excel file is only for additional data-columns in your dataextract-created Table or Excelfile!

> DWG:

[Blockname][AttributName1][AttributXYZ]

MyBlock1    A                 okey

MyBlock1    A                 hmm

MyBlock1    B                 yes

MyBlock2    100D           err

MyBlock2    B                 nice

> external linked Excelfile (only one possible example)

[AttributVal] [additionalcolumn]

A                 aaa

B                 bbb

you can link external-excel-data, the result could be:

[Blockname][AttributName1][AttributXYZ][additionalcolumn]

MyBlock1    A                     okey                aaa

MyBlock1    A                     hmm               aaa

MyBlock1    B                     yes                   bbb

MyBlock2    100D              err

MyBlock2    B                    nice                  bbb

[dans557JT]

I understand now. My intention was to extract and link every instance of data, but it appears that will not be possible. I will try to see if I can just get by without linking to external data.

CADffm, I am amazed at your ability to explain technical concepts in your non-native language (I noticed your AutoCAD language was set to German). I hope to be able to do this one day.

Thank you everyone for your input!

[dans557JT]

Once I receive a reply for John, I will accept a solution based on his response, or lack thereof.

[john.vellek]

Hi @dans557JT,

I was actually working on this again this morning.

Here is an excerpt from the HELP on this issue:

Understand Data Linking and Matching

Data linking is the process of selecting a Microsoft Excel spreadsheet with the purpose of merging all or some of its contents with extracted drawing data. See Link a Table to External Data for more information about data linking.

Data matching creates a relationship between two sets of data; the data in a column from the extracted drawing data and the data in a column from an Excel spreadsheet.

For example, you have a simple bill of materials (BOM). Three columns of data are extracted from a drawing. These columns contain data for: Part #, Revision, and Quantity. You want to include two additional columns of data in the BOM from a spreadsheet. These columns contain data for Cost and Supplier.

In this example, the spreadsheet contains a column of part numbers labeled Catalog Number that matches the Part Number column in the extracted data. In the Link External Data dialog box , you select Part # as the column for the drawing data and Catalog Number as the column for the external data. Because there is at least one cell of matching data in the drawing data column and the external data column, the data extraction feature “knows” how both sources are tied together.

You can test if the data matching is valid by clicking the Check Match button from the Link External Data dialog box. If the match is unsuccessful, a warning message indicates what the problem is. In some situations, the drawing data might not link correctly to the data in the spreadsheet.

So, to summarize, I created a new XLS that contained two columns:CatalagName, Color of Unit. I then ran the dataextraction and in the process linked to the new xls file. I linked the Name field from AutoCAD to the CATALOGNAME field in the spreadsheet. I then add the columns for the datatable.

You will see now in your drawing that the additional column is added to your table.

[john.vellek · Accepted solution]

Hi @dans557JT,

I was actually working on this again this morning.

Here is an excerpt from the HELP on this issue:

Understand Data Linking and Matching

Data linking is the process of selecting a Microsoft Excel spreadsheet with the purpose of merging all or some of its contents with extracted drawing data. See Link a Table to External Data for more information about data linking.

Data matching creates a relationship between two sets of data; the data in a column from the extracted drawing data and the data in a column from an Excel spreadsheet.

For example, you have a simple bill of materials (BOM). Three columns of data are extracted from a drawing. These columns contain data for: Part #, Revision, and Quantity. You want to include two additional columns of data in the BOM from a spreadsheet. These columns contain data for Cost and Supplier.

In this example, the spreadsheet contains a column of part numbers labeled Catalog Number that matches the Part Number column in the extracted data. In the Link External Data dialog box , you select Part # as the column for the drawing data and Catalog Number as the column for the external data. Because there is at least one cell of matching data in the drawing data column and the external data column, the data extraction feature “knows” how both sources are tied together.

You can test if the data matching is valid by clicking the Check Match button from the Link External Data dialog box. If the match is unsuccessful, a warning message indicates what the problem is. In some situations, the drawing data might not link correctly to the data in the spreadsheet.

So, to summarize, I created a new XLS that contained two columns:CatalagName, Color of Unit. I then ran the dtaextraction and in the process linked to the new xls file. I linked the Name field from AutoCAD to the CATALOGNAME field in the spreadsheet. I then add the columns for the datatable.

You will see now in your drawing that the additional column is added to your table.

[dans557JT]

Okay this is even more evidence that my understanding was incorrect on this. Linking to an external source appears to not be what I thought it was, and therefore I will need to figure something else out. 

Hopefully this thread will help someone else searching on this topic, as it appears, there is not much online regarding this. 

Thanks everyone!

[TheCADnoob · Accepted solution]

on the outside shot that all you want is a linked spread sheet here is a screen cast on what that looks like. 

https://knowledge.autodesk.com/community/screencast/0a37c7d8-71d3-491c-8f3f-81bbc619cc09