This article shows how to initialize the table grid with an external data source.
You can connect an external data source with your data to the grid using grid configuration.
In order to initialize a grid with an external data source you should do the following steps:
- Navigate to Data Source tab on the grid configuration page
Select previously created data source from the drop-down
We've added Jira database as a default option in the list. Now you don't need to connect you Jira database as a separate data source. It's already connected by default.v
Specify SQL query or JSONPath depending on the data source type
REST data source SQL data source 
Execute the query to get the data preview
REST data source SQL data source Try the example REST data source with users' data https://jsonplaceholder.typicode.com/users
Example of the data retrieved from the Jira Server database.
Configure columns mapping
Select columns from the data source to load information into previously created grid columns.Note!
Following column types could not display data from the extenral data source:
date, date/time. sequence, userlist and formula.In case you have these type of data in your data source, please map them into columns with string or text type.
REST data source SQL data source 
Save changes.
JQL search limitation
In case the grid is populated with data from an external data source you need to re-save it from the issue view to index external data.
Congratulations! Now you know how to initialize grid with an external data source.