Simple example of nested mappings, with queries that require a key to match as well.

analysis.yaml

# Here you could have various analyzers for different string-types.
# "text_value" and "name_value" should probably have different ones.

documents.yaml

_id: 12345678

fields:
    - key: book_title
      text_value: "Harry Potter"

    - key: price
      float_value: 34.50

---

_id: 123456790

fields:
    - key: blog_title
      text_value: "My awesome blog"

    - key: author
      name_value: "John Smith"

    # Just showing that both key and value must match above.
    - key: not_book_title
      text_value: "This blog is not about Harry Potter"

mappings.yaml

type:
    properties: 
        fields: 
            type: nested
            properties: 
                key: 
                    type: string
                    index: not_analyzed
                text_value: 
                    type: string
                    analyzer: simple
                name_value: 
                    type: string
                    # Should probably want a better analyzer. See https://www.found.no/play/gist/68ca8a4a50025560f822
                    # for an example on metaphone-based fuzzy name searching
        
                    analyzer: simple

play.sh

#!/bin/bash

export ELASTICSEARCH_ENDPOINT="http://localhost:9200"

# Create indexes

curl -XPUT "$ELASTICSEARCH_ENDPOINT/play" -d '{
    "settings": {
        "analysis": {}
    },
    "mappings": {
        "type": {
            "properties": {
                "fields": {
                    "type": "nested",
                    "properties": {
                        "key": {
                            "type": "string",
                            "index": "not_analyzed"
                        },
                        "text_value": {
                            "type": "string",
                            "analyzer": "simple"
                        },
                        "name_value": {
                            "type": "string",
                            "analyzer": "simple"
                        }
                    }
                }
            }
        }
    }
}'


# Index documents
curl -XPOST "$ELASTICSEARCH_ENDPOINT/_bulk?refresh=true" -d '
{"index":{"_index":"play","_type":"type","_id":12345678}}
{"fields":[{"key":"book_title","text_value":"Harry Potter"},{"key":"price","float_value":34.5}]}
{"index":{"_index":"play","_type":"type","_id":123456790}}
{"fields":[{"key":"blog_title","text_value":"My awesome blog"},{"key":"author","name_value":"John Smith"},{"key":"not_book_title","text_value":"This blog is not about Harry Potter"}]}
'

# Do searches

curl -XPOST "$ELASTICSEARCH_ENDPOINT/_search?pretty" -d '
{
    "query": {
        "nested": {
            "path": "fields",
            "query": {
                "filtered": {
                    "filter": {
                        "term": {
                            "key": "book_title"
                        }
                    },
                    "query": {
                        "match": {
                            "text_value": "potter"
                        }
                    }
                }
            }
        }
    }
}
'

curl -XPOST "$ELASTICSEARCH_ENDPOINT/_search?pretty" -d '
{
    "query": {
        "nested": {
            "path": "fields",
            "query": {
                "filtered": {
                    "filter": {
                        "bool": {
                            "must": [
                                {
                                    "term": {
                                        "key": "price"
                                    }
                                },
                                {
                                    "range": {
                                        "float_value": {
                                            "gt": 34
                                        }
                                    }
                                }
                            ]
                        }
                    }
                }
            }
        }
    }
}
'

play.yaml

# Auto generated by Found's Play-tool at 2013-11-22T09:24:06+01:00
version: 0
title: "Nested key/value-mapping"
description: "Simple example of nested mappings, with queries that require a key to match as well."

searches.yaml

# In reply to http://stackoverflow.com/questions/20138641/dynamic-type-with-mappings

query: 
    nested: 
        path: fields
        query: 
            filtered: 
                filter: 
                    term: 
                        key: book_title
                query: 
                    # This should not match the second document
                    match:
                        text_value: potter

---

query: 
    nested: 
        path: fields
        query: 
            filtered: 
                filter: 
                    bool: 
                        must: 
                            - term: 
                                  key: price
                            - range: 
                                  float_value: 
                                    gt: 34