Low Search - Multiple Select Problem

Question

I have this form

{exp:low_search:form collection="foo" query="{segment_2}" secure="no" search_mode="any" loose_ends="yes" result_page="test/"}

<label for="foo_gender">Gender:</label>     
<select class="span12" name="search:foo_gender[]" id="foo_gender" multiple="multiple">
    <option></option>
    {exp:channel:entries channel="genders" orderby="entry_id" sort="asc"}
        <option value="={gender}">{gender}</option>
    {/exp:channel:entries}
</select>

<button type="submit" class="btn btn-primary">Search</button>

{/exp:low_search:form}

In the database I have 3 entries

 Entry 1, foo_gender = Male
 Entry 2, foo_gender = Female
 Entry 3, foo_gender = Transgender

I tried selecting entry 1 and 2 and submit.

I got only 1 entry from the result, entry 1.

That search form was supposed to be returning 2 entries, entry 1 and 2

Why is this the case?

P.S

The output of {low_search_search:foo_gender[]} was "=Male|=Female"

Answer 1

Currently, Low Search only supports non-exact matching for the search:field parameters with multiple values only. Single value fields will work with the exact syntax. You could work around it in this case by making it a single value:

<select class="span12" name="search:foo_gender" id="foo_gender">
    <option value="">All</option>
    {exp:channel:entries channel="genders" orderby="entry_id" sort="asc"}
        <option value="={gender}">{gender}</option>
    {/exp:channel:entries}
</select>

Update

As of Low Search v2.2.0, this is now possible, with the exact="" parameter. Simplfied:

{exp:low_search:form exact="search:foo_gender"}

    <label for="foo_gender">Gender:</label>  
    <select name="search:foo_gender[]" id="foo_gender" multiple="multiple">
        {exp:channel:entries channel="genders"}
            <option value="{gender}">{gender}</option>
        {/exp:channel:entries}
    </select>

{/exp:low_search:form}