Accessing Data
Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012
Queries enable you to ask questions about the data in the Microsoft Dynamics AX database and retrieve information. There are two ways to create queries:
Use the Queries node in the Application Object Tree (AOT) to create static queries using a graphical interface. For more information, see How to: Create Queries by using the AOT.
Use the query system classes to create dynamic queries in code. For more information, see How to: Create Queries by Using X++.
No matter which method that you use to create a query, the query can include a sorting order to sort the information that is returned. It can also include a range to filter the information that is returned based on your criteria.
A query can return data from multiple data sources. For more information, see How to: Add Multiple Data Sources to a Query.
You can create queries for forms and reports. For more information, see How to: Coordinate Two Forms by Overriding an Event Method.
Paging
When you create a query with X++, you can add paging support to that query. Paging retrieves the results of a query as a collection of one or more data subsets known as pages. The QueryRun class supports the following types of paging:
Position based paging divides the query result into pages and enables you to display the data records represented by a specified page.
Value based paging uses a page to represent the data records that are currently displayed in a data grid. Use value based paging when you want an update to a data grid to automatically redisplay the same set of data records.
To enable paging, use the enablePositionPaging and enableValueBasedPaging methods of the QueryRun class. To use paging with a query, the query cannot have a disabled data source. Also, the value of the FirstOnly property of the data source must be set to No.
See also
Using Expressions in Query Ranges
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