This alert is raised when the profiler detect that a query was generated from the view in an MVC application. Issuing queries from the view is a bad practice for several reasons.
- It increase the time that the connection to the database have to be open. The recommendation is to keep that open only for the duration of the action, not throughout the lifetime of the request.
- It make it that much harder to understand what are the data requirements for a particular action is.
- When writing views, you shouldn't be bothered with thinking about persistence, or the number of queries that you views are generating.
- The views are often the most changeable parts in the application, and having the application issue queries from the views may result in significant changes to the way the application data access pattern between revisions.
- Most often, queries from the views result from lazy loading, Select N+1 or similar bad practices.
We strongly recommend that you'll avoid generating queries in the view, instead, perform all your queries in the action, and provide in memory access only to the view for them to render themselves.