example of ES parent-child mapping + query syntax

mappings.txt

# topic mappings
POST /index/topic/_mapping -d '{
  "topic": {
    "properties": {
      "section_id": { "type": "integer" },
      "title": { "type": "string" },
      "message": { "type": "string" },
      "post_count": { "type": "integer" },
      "status": { "type": "string", "index": "not_analyzed" },
      "created_at": { "type": "integer" },
      "updated_at": { "type": "integer" }
    }
  }
}'

# comment mappings
POST /index/comment/_mapping -d '{
  "comment": {
    "_parent": { "type": "topic" },
    "properties": {
      "message": { "type": "string" },
      "username": { "type": "string", "index": "not_analyzed" },
      "status": { "type": "string", "index": "not_analyzed" },
      "created_at": { "type": "integer" },
      "updated_at": { "type": "integer" }
    }
  }
}'

query-array.php

<?php                                                                           
$query = array('bool' => array(                                                 
  'should' => array(                                                            
    array(
      'has_child' => array(                                                     
        'type' => 'comment',                                                       
        'score_type' => 'sum',
        'query' => array(
          'query_string' => array(
            'fields' => array('message^1.2'),
            'query' => $query_string
          )
        )
      )
    ),
    array(
      'query_string' => array(
        'fields' => array('title^2', 'message^1.2'),
        'query' => $query_string
      )
    )
  )
));
?>