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. |
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