:multi_attr

You can use plugin functions in a `filter` clause to filter data, and use functions that return numeric values in a `sort` clause to sort data.

Document fields used as function parameters must be created as indexes or properties.

1. Usage:

multi_attr(field, pos, default_value=0|"")

2. Parameters:

field: The name of the field to query. The field must be an ARRAY type and configured as an attribute field. pos: An integer constant or an integer field. If an integer field is specified, it must be configured as an attribute field. The index is 0-based. default_value(sorting score): Optional. A string constant. This value is returned if a value does not exist at the specified position.

3. Return value:

• If the `value` at the specified `pos` exists, the `function` returns the `value` at that `index` in the `array`.

• If the `value` at the specified `pos` does not exist and the `default_value` parameter is not set, the `function` returns 0.

• If the `value` at the specified `pos` does not exist and the `default_value` parameter is set, the `function` returns the `default_value`.

4. Scenarios:

Scenario 1: A product has multiple prices, such as market price, discount price, and sales price, stored in the `prices` field. Query for mobile phones with a sales price less than 1000.

query=deault:'phone'&&filter=multi_attr(price,2)<1000

Scenario 2: A product has multiple prices, such as market price, discount price, and sales price, stored in the `prices` field. Sort the `query` results in ascending order by the discount price. If the discount price does not exist or the `prices` field is `empty`, use a `default` `value` of 600.

query=default:'mobile phone'&&sort=+multi_attr(price,1,"600")

5. Notes:

• Fields used as `function` parameters must be created as properties.

• Enclose the `default_value` in double quotation marks.