A good overview of Query List is at this blog: Query List Action Provides Powerful Workflow Capabilities to NITRO Studio
Query List functionality is explained in detail in this article on our Support site: https://www.crowcanyon.help/article/470/
Refer Query List action for more detail
As stated in that help article, the Query List action is very useful when items are related to each other and actions need to be taken on these related items. Query List gets those items and then allows them to be used in subsequent actions in the Custom Action that is running.
From the article:
"Query List action is used to retrieve one or more items of a list as per the defined criteria. For example, get all open Tasks related to a Ticket or get all line items for a Purchase Request. Retrieved list items can then be used in other actions, some examples of this usage are given below:
•Cancel all open Tasks of the Ticket when Ticket is canceled
•Calculate the sum of cost of all line items
•Create an Asset for each of the line items of a Purchase Request
•Check if all Tasks related to a Request are ‘Closed’ and if so then mark the Request as Completed
Custom Actions are used extensively in NITRO based applications and Query List action is indispensable whenever we have to deal with items that are related to each other."
See details at the above mentioned link.
Query List action in designer custom action
