DevExtreme Angular - Query API
To create a Query, call the query(array) or query(url, queryOptions) method, depending on the type of the storage you access. The Query supports method chaining. This enables you to execute several methods in a single statement.
- import Query from "devextreme/data/query";
- // ...
- export class AppComponent {
- constructor() {
- let dataObjects = [
- { name: "Amelia", birthYear: 1991, gender: "female" },
- { name: "Benjamin", birthYear: 1983, gender: "male" },
- { name: "Daniela", birthYear: 1987, gender: "female" },
- { name: "Lee", birthYear: 1981, gender: "male" }
- ];
- let processedArray = Query(dataObjects)
- .filter([ "gender", "=", "female" ])
- .sortBy("birthYear")
- .select("name", "birthYear")
- .toArray();
- }
- }
See Also
Methods
Name | Description |
---|---|
aggregate(seed, step, finalize) |
Calculates a custom summary for all data items. |
aggregate(step) |
Calculates a custom summary for all data items. |
avg() |
Calculates the average of all values. Applies only to numeric arrays. |
avg(getter) |
Calculates the average of all values found using a getter. |
count() |
Calculates the number of data items. |
enumerate() |
Executes the Query. This is an asynchronous alternative to the toArray() method. |
filter(criteria) |
Filters data items using a filter expression. |
filter(predicate) |
Filters data items using a custom function. |
groupBy(getter) |
Groups data items by the specified getter. |
max() |
Calculates the maximum value. Applies only to numeric arrays. |
max(getter) |
Calculates the maximum of all values found using a getter. |
min() |
Calculates the minimum value. Applies only to numeric arrays. |
min(getter) |
Calculates the minumum of all values found using a getter. |
select(getter) |
Selects individual fields from data objects. |
slice(skip, take) |
Gets a specified number of data items starting from a given index. |
sortBy(getter) |
Sorts data items by the specified getter in ascending order. |
sortBy(getter, desc) |
Sorts data items by the specified getter in the specified sorting order. |
sum() |
Calculates the sum of all values. |
sum(getter) |
Calculates the sum of all values found using a getter. |
thenBy(getter) |
Sorts data items by one more getter in ascending order. |
thenBy(getter, desc) |
Sorts data items by one more getter in the specified sorting order. |
toArray() |
Gets data items associated with the Query. This is a synchronous alternative to the enumerate() method. |
If you have technical questions, please create a support ticket in the DevExpress Support Center.