Data Query Overview
The Data Query is a package for applying the sorting, filtering, grouping, and aggregate data operations.
The package exports functions which help you perform in-memory data operations. It also serializes the data descriptors according to the OData v4 URI specification.
Installation
-
Download and install the package:
npm install --save @progress/kendo-data-query -
Once installed, you can import individual functions and then use the Data Query package.
import { process, orderBy, filterBy, /* etc...*/ } from '@progress/kendo-data-query';
Process Helpers for Bulk Operations
The Data Query provides functions that help you handle the following bulk data operations:
The following example demonstrates how to group, sort, and filter data by using a single helper function.
import { process } from '@progress/kendo-data-query';
const data = [
{ "productName": "Chai", "unitPrice": 18, "unitsInStock": 39, "discontinued": false,
"category": { "categoryName": "Beverages" }
},
{ "productName": "Chang", "unitPrice": 19, "unitsInStock": 17, "discontinued": false,
"category": { "categoryName": "Beverages" }
},
{ "productName": "Aniseed Syrup", "unitPrice": 10, "unitsInStock": 13, "discontinued": false,
"category": { "categoryName": "Condiments" }
},
{ "productName": "Cajun Seasoning", "unitPrice": 22, "unitsInStock": 53, "discontinued": false,
"category": { "categoryName": "Condiments" }
},
{ "productName": "Gumbo Mix", "unitPrice": 21.35, "unitsInStock": 0, "discontinued": true,
"category": { "categoryName": "Condiments" }
}
];
const result = process(data, {
group: [{
field: 'category.categoryName',
aggregates: [
{ aggregate: "sum", field: "unitPrice" },
{ aggregate: "sum", field: "unitsInStock" }
]
}],
sort: [{ field: 'productName', dir: 'desc' }],
filter: {
logic: "or",
filters: [
{ field: "discontinued", operator: "eq", value: true },
{ field: "unitPrice", operator: "lt", value: 22 }
]
}
});
console.log(JSON.stringify(result, null, 2));
/* output
{
"data": [
{ "aggregates": {
"unitPrice": { "sum": 53.35 },
"unitsInStock": { "sum": 66 }
},
"field": "category.categoryName",
"items": [
{ "productName": "Gumbo Mix", "unitPrice": 21.35, "unitsInStock": 0, "discontinued": true,
"category": { "categoryName": "Condiments" }
},
{ "productName": "Aniseed Syrup", "unitPrice": 10, "unitsInStock": 13, "discontinued": false,
"category": { "categoryName": "Condiments" }
}
],
"value": "Condiments"
},
{
"aggregates": {
"unitPrice": { "sum": 37 },
"unitsInStock": { "sum": 56 }
},
"field": "category.categoryName",
"items": [
{ "productName": "Chang", "unitPrice": 19, "unitsInStock": 17, "discontinued": false,
"category": { "categoryName": "Beverages" }
},
{ "productName": "Chai", "unitPrice": 18, "unitsInStock": 39, "discontinued": false,
"category": { "categoryName": "Beverages" }
}
],
"value": "Beverages"
}
],
"total": 4
}
*/
Sorting
To sort an array of objects based on a field and direction, use the orderBy helper function. The method accepts a data array and one or more SortDescriptors.
import { orderBy } from '@progress/kendo-data-query';
const data = [
{ name: "Pork", category: "Food", subcategory: "Meat" },
{ name: "Pepper", category: "Food", subcategory: "Vegetables" },
{ name: "Beef", category: "Food", subcategory: "Meat" }
];
const result = orderBy(data, [{ field: "name", dir: "asc" }]);
console.log(result);
/* output
[
{ "name": "Beef", "category": "Food", "subcategory": "Meat" },
{ "name": "Pepper", "category": "Food", "subcategory": "Vegetables" },
{ "name": "Pork", "category": "Food", "subcategory": "Meat" }
]
*/
Filtering
To filter an array of objects, use the filterBy helper function. The method accepts a data array and one or more FilterDescriptors.
import { filterBy } from '@progress/kendo-data-query';
const data = [
{ name: "Pork", category: "Food", subcategory: "Meat" },
{ name: "Pepper", category: "Food", subcategory: "Vegetables" },
{ name: "Beef", category: "Food", subcategory: "Meat" }
];
const result = filterBy(data, {
logic: 'and',
filters: [
{ field: "name", operator: "startswith", value: "p", ignoreCase: true },
{ field: "subcategory", operator: "eq", value: "Meat" },
]
});
console.log(JSON.stringify(result, null, 2));
/* output
[
{ "name": "Pork", "category": "Food", "subcategory": "Meat" }
]
*/
Grouping
To split the data array into sets, use the groupBy helper function. The method accepts a data array and one or more GroupDescriptors.
import { groupBy } from '@progress/kendo-data-query';
const data = [
{ name: "Pork", category: "Food", subcategory: "Meat" },
{ name: "Pepper", category: "Food", subcategory: "Vegetables" },
{ name: "Beef", category: "Food", subcategory: "Meat" }
];
const result = groupBy(data, [{ field: "category" }, { field: "subcategory", dir: "desc" }]);
console.log(JSON.stringify(result, null, 2));
/* output
[
{ "aggregates": {}, "field": "category",
"items": [
{"aggregates": {}, "field": "subcategory",
"items": [
{ "name": "Pork", "category": "Food", "subcategory": "Meat" },
{ "name": "Beef", "category": "Food", "subcategory": "Meat" }
],
"value": "Meat"
},
{ "aggregates": {}, "field": "subcategory",
"items": [
{"name": "Pepper", "category": "Food", "subcategory": "Vegetables"}
],
"value": "Vegetables"
}
],
"value": "Food"
}
]
*/
Aggregates
To aggregate data based on the AggregateDescriptor, use the aggregateBy helper function.
import { aggregateBy } from '@progress/kendo-data-query';
const data = [
{ "productName": "Chai", "unitPrice": 18, "unitsInStock": 39 },
{ "productName": "Chang", "unitPrice": 19, "unitsInStock": 17 },
{ "productName": "Aniseed Syrup", "unitPrice": 10, "unitsInStock": 13 }
];
const result = aggregateBy(data, [
{ field: 'productName', aggregate: 'count' },
{ field: 'unitPrice', aggregate: 'sum' },
{ field: 'unitPrice', aggregate: 'average' },
{ field: 'unitsInStock', aggregate: 'min' },
{ field: 'unitsInStock', aggregate: 'max' },
]);
console.log(JSON.stringify(result, null, 2));
/* output
{
"productName": { "count": 3 },
"unitPrice": { "sum": 47, "average": 15.666666666666666 },
"unitsInStock": { "min": 13, "max": 39 }
}
*/