Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Creating a Screen Based on a Query

Creating a LightSwitch Screen Based on a Query

In this lesson, you'll create a LightSwitch screen that's based on a query. By creating the query first, you can limit the amount of data that the associated screen shows.

An earlier lesson, Creating a Basic Query in LightSwitch, showed how to use a query to filter the results on a screen that was originally created from the Orders entity. By creating a screen that's directly based on a query, you can restrict the amount of data that appears and control the sort order.

To create a screen from a query

  1. In Solution Explorer, open the shortcut menu for the Products.lsml node, and then choose Add Query.

    The Query Editor appears.

  2. In the Properties window, name the query CurrentProducts.

  3. In the Query Designer, choose the Add Filter link.

  4. In the first list, choose Where.

  5. In the second list, choose Discontinued.

    Notice that the final list value changes to False.

  6. In the Query Designer, choose the Add Sort link.

  7. In the first list, choose ProductName.

  8. In Solution Explorer, open the shortcut menu for the Screens node, and then choose Add Screen.

    The Add New Screen dialog box appears.

  9. In the Select a screen template list, choose Browse Data Screen.

  10. In the Screen Name text box, enter CurrentProductList.

  11. In the Screen Data list, choose – CurrentProducts, and then choose the OK button.

  12. In the center pane of the Screen Designer, choose the Rows Layout | rows node. In the Add list, choose Discontinued.

  13. Run the application and open the Current Product List screen.

    Notice that only products that haven't been discontinued (the discontinued field displays false) appear and that they're listed in alphabetical order.

This lesson showed how to create a query to select products that haven’t been discontinued, and then to create a screen to display the results of that query. If you had created the screen from the Products entity, the results would have included all products, including discontinued ones. By creating a query first, you limited the data that’s shown on the associated screen.

This type of query is known as a global query; it can be reused on multiple screens. A global query can also be used as the source for a new global query as long as both return the same entity type.

In the next lesson, you’ll learn how to create a parameterized query.

Next lesson: Creating a Parameterized Query in LightSwitch

© 2015 Microsoft