Include Custom Fields
Determines if the custom fields created on a card will be shown.
Custom Fields is one of the most popular power ups found on Trello. To begin using Custom fields, first activate the power up in your Trello board and create/add custom fields to your cards. After you are done setting up the power up and adding custom fields, set this connection property to true and the custom fields will appear as columns in the Cards table.
Please note that you must also specify the BoardId in the connection string. This connection property is used for retrieving custom fields that have been created on Trello's cards.
SELECT * FROM CardsRunning the query above will list all the custom fields created as table columns.