How do I get the reverse entries of a relationship field? [duplicate]

Question

I have a multi-site with two different channels:

1. Guides
2. Rivers

I need to associate specific guides with each river. Each river can have multiple guides associated with them.

Currently, I have it setup so the Rivers have a relationship field that allows selecting of entries from guides channel. That's working perfectly, but I'm running into an issue trying to list all of the Rivers a Guide is associated with.

For example: I have the river Salmon with a relationship of Guide A, Guide B and Guide C. On the Salmon River's page, it displays Guide A, Guide B and Guide C.

When I click on Guide A, I want that page to display all of the Rivers that have Guide A selected in the River's relationship field, i.e. Salmon River, Main Payette, etc.

Answer 1

You need to use a reverse relationship tag {parents}, it's well documented (with a Pizza Shop example) here on the EE docs site : https://ellislab.com/expressionengine/user-guide/add-ons/channel/relationships.html#parent-entries-which-stores-have-which-pizza

For example :

{!-- assuming here the guide being displayed is entry ID of 1 --}
{exp:channel:entries channel="guides" entry_id="1"}

    <h2>Guide : {title}</h2>

    <p>Rivers this guide applies to:</p>
    <ul>

    {!-- Here, the field parameter needs to be the field id of the relationship field on the rivers channel --}
    {parents field="river_guides"}
        <li>{parents:title}</li>
    {/parents}
{/exp:channel:entries}

And yes this is a duplicate. Let us know how you get on though please.

Also, you don't actually mention if your relationship fields are in a grid or matrix, are they? If so this answer might be of use to you : Parent relationship in grid field type