Replacing the Data Source in Tableau Software without errors

Tableau is a powerful tool for Data Visualization. As a Consultant Data Analyst, I worked for several clients (from Big Companies to Startup). I’ve learned that even though we can do a lot of things on Tableau, some tasks may be a bit messy. 

I recently had to change a dashboard’s data source and animate a workshop to explain the process to the Data Team of the company I am currently working with. That’s what we are going to talk about in this article !

1. Context

You may want to change the dashboard’s data source for a lot of reasons : 

• Migrating your database infrastructure
• Evaluating a new method of computation for your indicators in the data source
• Using production database instead of the staging one

If you want this task to succeed, avoid a lot of errors and save time, you must follow some steps. 

2. Errors encountered 

If you replace the data source without preparing your new source, you face the risks of having the following errors : 

• Duplicate fields with (1) added to the name 
• ! at the end of a field (calculated or not) 
• Fields with wrong names 

In the end, every field is in red, your KPIs are gone and the Dashboard is down.

3. Steps to follow

To avoid errors and before replacing the source, you have to prepare the new source so the fields in common (names and types) are identical between the two sources :

• Rename fields from both data sources 
• Convert fields of the new source in Dimensions / Measures if needed 
• Convert the type of the fields from the new source (integers, string, etc. and Discrete / Continue) if needed

4. Rename fields from both data sources

If not already done, you should add the new data source to your dashboard. 

You have to repeat the following actions for both data sources.

First, go into Data > Select the Data Source > Edit Data Source. Then, focus on the table with all of the field in the left bottom corner.

Left-click on one of the fields in the column Field Name, select all (CTRL + A), then right-click and apply “Reset Names”.

All the names have been reset, any renaming (manual or from Tableau itself) is deleted.

Warning : If you use data blending, the connection between your sources will break due to the renaming. You have to rename the field after the source has been replaced or rename the field from the other source involved in the data blending.

5. Convert the fields

The fields’ types of the new data source that are in the old one must match exactly.

I strongly recommend opening the dashboard twice so you can compare the lists of fields.

Here, you can see that there are differences between the sources :

• age is a Measure in the New Source
• id is an Integer in the New Source

You want the new source to match exactly the old source. So you have to convert :

• age in Dimension
• id in string

6. Replacing the data source without errors

Now that your data sources matches (at least, the common fields. If your new data source has new fields, that won’t be a problem), you can replace the data source.

7. Conclusion

If you followed the steps, you shouldn’t have any errors. And if you have some, it means that you missed a field — no big deal, revert the action and convert the field(s)— . 

I hope you enjoyed this guide to replace the data source of a Dashboard on Tableau Server / Desktop without errors.

Let me know in the comments if you have any questions ! 

This article was originally published on Medium : https://medium.com/@vdebande/replacing-the-data-source-in-tableau-without-errors-13ff9b34aaa3

#data #tableau #dashboards