Query and Related Classes

The following classes define arbitrary search methods and filter conditions, and provide methods for combining test criteria and dynamically querying result sets.

Query and Related Classes
Class	Description
Query	Defines arbitrary search methods and can be composed of search conditions, object/row state filter conditions, and data ordering information.
AttributeTest	Defines filter conditions for MBO attributes.
CompositeTest	Contains a method to combine test criteria using the logical operators AND, OR, and NOT to create a compound filter.
QueryResultSet	Provides for querying a result set for the dynamic query API.
SelectItem	Defines the entry of a select query. For example, "select x.attr1 from MBO x", where "X.attr1" represents one SelectItem.
Column	Used in a subquery to reference the outer query's attribute.

In addition queries support select, where, and join statements.

Arbitrary Find
The arbitrary find method lets custom device applications dynamically build queries based on user input. The Query.DISTINCT property has been added so you can exclude duplicate entries from the result set.
AttributeTest
An AttributeTest defines a filter condition using an MBO attribute, and supports multiple conditions.
Aggregate Functions
You can use aggregate functions in dynamic queries.
Grouping Results
Apply grouping criteria to your results.
Concatenating Queries
Concatenate two queries having the same selected items.
Subqueries
Execute subqueries using clauses, selected items, and attribute test values.
CompositeTest
A CompositeTest combines multiple TestCriteria using the logical operators AND, OR and NOT to create a compound filter.
Complex Example
This example shows the usage of CompositeTest, SortCriteria and Query to locate all customer objects based on particular criteria.
QueryResultSet
The QueryResultSet class provides for querying a result set for the dynamic query API. QueryResultSet is returned as a result of executing a query.

Parent topic: Retrieving Data from Mobile Business Objects