<?xml version="1.0" encoding="UTF-8"?>
<model package="crm" baseClass="xPDOObject" platform="mysql" defaultEngine="MyISAM" version="1.1">
<object class="Client" table="client" extends="xPDOSimpleObject">
<field key="name" dbtype="varchar" precision="200" phptype="string" null="true" />
<field key="email" dbtype="varchar" precision="200" phptype="string" null="true" />
<field key="phone" dbtype="varchar" precision="200" phptype="string" null="true" />
<field key="url" dbtype="varchar" precision="200" phptype="string" null="true" />
<field key="message" dbtype="varchar" precision="512" phptype="string" null="true" />
<field key="deleted" dbtype="int" precision="11" phptype="integer" null="false" default="0" />
<field key="published" dbtype="int" precision="11" phptype="integer" null="false" default="1" />
<index alias="id" name="id" primary="false" unique="true" type="BTREE" >
<column key="id" length="" collation="A" null="false" />
</index>
<composite alias="ClientPhoto" class="ClientPhoto" local="id" foreign="photo_client_id" cardinality="many" owner="local" />
</object>
<object class="ClientPhoto" table="client_photo" extends="xPDOSimpleObject">
<field key="photo_name" dbtype="varchar" precision="255" phptype="string" null="true" />
<field key="photo_client_id" dbtype="int" precision="11" phptype="integer" null="true" />
<field key="photo_file" dbtype="varchar" precision="20" phptype="string" null="true" />
<field key="deleted" dbtype="int" precision="11" phptype="integer" null="false" default="0" />
<field key="published" dbtype="int" precision="11" phptype="integer" null="false" default="1" />
<index alias="id" name="id" primary="false" unique="true" type="BTREE" >
<column key="id" length="" collation="A" null="false" />
</index>
<aggregate alias="Client" class="Client" local="photo_client_id" foreign="id" cardinality="one" owner="foreign" />
</object>
</model>

your clientPhotos - field has to be a intputTVtype 'migxdb'
with its own config.
In the config for this grid, you need
joinalias: Client
has Connection table: no
check Resource: yes
