filter( )

Filters out items from being used in an aggregation.

Description

The filter() function refines a WixDataAggregate so that it only includes items from the aggregate's collection which match the specified filter criteria.

To create a filter, use the wix-data filter() function.

Filtering using filter() takes place before grouping is performed on the aggregation. To filter grouped results, use the having() function.

Note: Aggregations can only be used on collections you have created. They cannot be used on Wix App Collections.

Syntax

function filter(filter: WixDataFilter): WixDataAggregate

filter Parameters

NAME

TYPE

DESCRIPTION

filter

WixDataFilter

The filter to use to filter out items from being used in the aggregation.

Returns

A WixDataAggregate object representing the refined aggregation.

Return Type:

WixDataAggregate

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Filter out items in an aggregation

Copy Code

1let filter = wixData.filter().eq("year", 2010);
2
3let newAggregate = aggregate.filter(filter);

Filter out items in an aggregation and run the aggregation

Copy Code

1import wixData from 'wix-data';
2
3// ...
4
5let filter = wixData.filter().eq("year", 2010);
6
7wixData.aggregate("PopulationData")
8  .filter(filter)
9  .max("population", "maxPopulation")
10  .run()
11  .then((results) => {
12    if (results.items.length > 0) {
13      let items = results.items;        // see below
14      let numItems = results.length;    // 1
15      let hasNext = results.hasNext();  // false
16    } else {
17      // handle case where no matching items found
18    }
19  })
20  .catch((error) => {
21    let errorMsg = error.message;
22    let code = error.code;
23  });
24
25// items is: [{"_id":"0","maxPopulation":8192000}]

Create an aggregation with filtering and grouping and run it

Copy Code

1import wixData from 'wix-data';
2
3// ...
4
5const filter = wixData.filter().eq("year", 2010);
6const having = wixData.filter().gt("maxPopulation", 1000000);
7
8wixData.aggregate("PopulationData")
9  .filter(filter)
10  .group("state")
11  .max("population", "maxPopulation")
12  .having(having)
13  .descending("maxPopulation")
14  .skip(5)
15  .limit(3)
16  .run()
17  .then((results) => {
18    if (results.items.length > 0) {
19      let items = results.items;
20      let numItems = results.length;
21      let hasNext = results.hasNext();
22    } else {
23      // handle case where no matching items found
24    }
25  })
26  .catch((error) => {
27    let errorMsg = error.message;
28    let code = error.code;
29  });