Query
An universal chainable data query interface object.
To create a Query, call the query(array) or query(url, queryOptions) utility function, depending on the type of storage you access. The Query enables you to execute several methods in a single statement, as it supports method chaining.
var processedArray = DevExpress.data.query(inputArray)
.filter([ [ "value", ">=", 10 ], "and", [ "value", "<=", 90 ]])
.sortBy("lastName")
.thenBy("firstName")
.select("lastName", "firstName", "value")
.toArray();For more information on the Query concept, refer to the Data Layer article.
Methods
This section describes the methods used to access the data associated with the Query.
| Name | Description |
|---|---|
| aggregate(seed, step, finalize) | Calculates a custom summary for the items in the current Query. |
| aggregate(step) | Calculates a custom summary for the items in the current Query. |
| avg() | Calculates the average item value for the current Query, if each Query item has a numeric type. |
| avg(getter) | Calculates the average item value for the current Query. |
| count() | Returns the total count of items in the current Query. |
| enumerate() | Executes the Query. |
| filter(criteria) | Filters the current Query data. |
| filter(predicate) | Filters the current Query data. |
| groupBy(getter) | Groups the current Query data. |
| max() | Finds the item with the maximum value in the Query. |
| max(getter) | Finds the item with the maximum getter value. |
| min() | Finds the item with the minimum value in the Query. |
| min(getter) | Finds the item with the minimum getter value. |
| select(getter) | Applies the specified transformation to each item. |
| slice(skip, take) | Limits the data item count. |
| sortBy(getter) | Sorts current Query data. |
| sortBy(getter, desc) | Sorts current Query data. |
| sum() | Calculates the sum of item values in the current Query. |
| sum(getter) | Calculates the sum of item getter values in the current Query. |
| thenBy(getter) | Adds one more sorting condition to the current Query. |
| thenBy(getter, desc) | Adds one more sorting condition to the current Query. |
| toArray() | Returns the array of current Query items. |