When you use add fields and switch objects in the same window it's retaining the previous selections.
Steps to reproduce:
Open a new query tab
Select an object and click add fields and select a field (ex. Contact > CreatedDate)
Execute a query
In the same tab change the record to another object (ex. Account)
Clear the existing query
Click on add fields and select a field (ex. Name)
Click add
The query will include the previous selected field (ex. CreatedDate) as well as the new field (ex. Name)
When you use add fields and switch objects in the same window it's retaining the previous selections.
Steps to reproduce:
Open a new query tab
Select an object and click add fields and select a field (ex. Contact > CreatedDate)
Execute a query
In the same tab change the record to another object (ex. Account)
Clear the existing query
Click on add fields and select a field (ex. Name)
Click add
The query will include the previous selected field (ex. CreatedDate) as well as the new field (ex. Name)