Package: django-pgjsonb
# django-pgjsonbDjango Postgres JSONB Fields support with lookupsOriginaly inspired by [django-postgres](https://bitbucket.org/schinckel/django-postgres/)Change Logs===========2017-09-13: 0.0.29Fix JsonAdapter Python2 incompatible2017-09-11: 0.0.28Fix contained_by contains empty {}Fix error of has_any/ has_allFix lookup ```filter(meta={})```2017-08-31: 0.0.27Fix as_{} lookup for python32017-08-31: 0.0.26Fix has lookup after Django 1.102017-05-18：0.0.25Supress exception when drop index and the index already removed.2017-03-14: 0.0.24Add support for __near lookup with postgres earthdistance plugin, Thanks to @steinliber2016-06-01: 0.0.23Fix value from select_json not been decode from json introduce by 0.0.182016-03-24: 0.0.22Fix error #11 remove the unexpect decode float to Decimal2016-03-19: 0.0.21Fix error #102016-03-09: 0.0.20Add the array length for select_json2016-03-08: 0.0.19fix when add a json field with db_index=True and it's fail to generate the create index sql2016-03-01: 0.0.18we want to be able to use customize decoder to load json, so get avoid the psycopg2's decode json, just return raw text then we deserilize by the field from_db_value2016-03-01: 0.0.17patch the django serilizer to not return the stringifyed result2015-07-23: 0.0.16Add support for ./manage.py inspectdb2015-06-10: 0.0.15Add support for db_index to add GIN indexInstall=======`pip install django-pgjsonb`Definition===```pythonfrom django_pgjsonb import JSONFieldclass Article(models.Model):meta=JSONField([null=True,default={},decode_kwargs={},encode_kwargs={},db_index=False,db_index_options={}])```Encoder and Decoder Options===by define decode_kwargs and encode_kwargs you can use your customize json dump and load behaveior, basicly these parameters will just pass to json.loads(**decode_kwargs) and json.dumps(**encode_kwargs)here is an example for use [EJSON](https://pypi.python.org/pypi/ejson) to store native datetime object```pythonimport ejsonclass Article(models.Model):meta=JSONField(encode_kwargs={"cls":ejson.EJSONEncoder},decode_kwargs={"cls":ejson.EJSONDecoder})```Add Index=====[new add in 0.0.15]jsonb field support gin type index to accelerator filtering. Since JSON is a data structure contains hierarchy, so the index of jsonb field will be more complicate than another single value field. More information, please reference [Postgres document 8.14.4](http://www.postgresql.org/docs/9.4/static/datatype-json.html)```pythonmeta=JSONField(db_index=True)ormeta=JSONField(db_index=True,db_index_options={"path":"authors__name","only_contains":True})ormeta=JSONField(db_index=True,db_index_options=[{},{"path":"authors__name","only_contains":True}])```When set db_index as True and do not set db_index_options, it will generate default GIN index, most case it's enough.When specify ```db_index_options={"only_contains":True}```, the index will be as the non-default GIN operator class jsonb_path_ops that supports indexing the ```contains``` operator only, but it's consume less space and more efficient.When specify the path parameter in db_index_options, ```db_index_options={"path":"authors__name"}```, then index will generate to the specify path, so that ```Article.objects.filter(meta__authors__name__contains=["asd"])``` can utilize the index.So you can create multiple index in one JSONField, just pass the db_index_options parameter as a list that contains multiple options, it will generate multiple correspond indexes. Empty dict stand for the default GIN index.Lookups=======###Contains a wide range of lookups supported natively by postgres1. `has` :if field has specific key *`("?")`*```pythonArticle.objects.filter(meta__has="author")```2. `has_any` : if field has any of the specific keys *`("?|")`*```pythonArticle.objects.filter(meta__has_any=["author","date"])```3. `has_all` : if field has all of the specific keys *`("?&")`*```pythonArticle.objects.filter(meta__has_all=["author","date"])```4. `contains` : if field contains the specific keys and values *`("@>")`*```pythonArticle.objects.filter(meta__contains={"author":"yjmade","date":"2014-12-13"})```5. `in` or `contained_by` : if all field key and value  contain by input *`("<@")`*```pythonArticle.objects.filter(meta__in={"author":"yjmade","date":"2014-12-13"})```6. `len` : the length of the array, transform to int, and can followed int lookup like gt or lt *`("jsonb_array_length()")`*```pythonArticle.objects.filter(meta__authors__len__gte=3)Article.objects.filter(meta__authors__len=10)```7. `as_(text,int,float,bool,date,datetime)` : transform json field into specific data type so that you can follow operation of this type *`("CAST(FIELD as TYPE)")`*```pythonArticle.objects.filter(meta__date__as_datetime__year__range=(2012,2015))Article.objects.filter(meta__view_count__as_float__gt=100)Article.objects.filter(meta__title__as_text__iregex=r"^\d{4}")```8. `path_(PATH)` : get the specific path, path split by '_' *`("#>")`*```pythonArticle.objects.filter(meta__path_author_articles__contains="show me the money")```Extend function to QuerySet========================1.`select_json("JSON_PATHS",field_name="JSON_PATHS")`JSON_PATHS in the format of paths separated by "__",like "meta__location__geo_info". It will use the queryset's `extra` method to transform a value inside json as a field.If no field_name provided, it will generate a field name with lookups separate by _ without the json field self's name, so `select_json("meta__author__name")` is equal to `select_json(author_name="meta__author__name")````pythonArticle.objects.select_json("meta__author__name",geo="meta__location__geo_info")````This operation will translate to sql as```sqlSELECT "article"."meta"->'location'->'geo_info' as "geo", "article"."meta"->'author'->'name' as "author_name"```[new add in 0.0.20]You can also select the length of a json array as a field by use Length object```pythonfrom django_pgjsonb.fields import LengthArticle.objects.select_json(authors_len=Length("meta__authors")).values("authors_len")```After select_json, the field_name can be operate in values() and values_list() method, so that1. select only one specific value inside json2. to group by one value inside jsonis possible.Demo:```pythonArticle.objects.all().select_json(tags="meta__tags").values_list("tags")# select only "meta"->'tags'Article.objects.all().select_json(author_name="meta__author__name")\.values("author_name").annotate(count=models.Count("author_name"))# GROUP BY "meta"->'author'->'name'```support geo search in jsonb===========================**require**: postgresql plugin:1. cube2. earthdistance3. to install these two plugin, run command below in psql```CREATE EXTENSION cube;CREATE EXTENSION earthdistance;```how to save location  json record```Json{"location": [30.2, 199.4]}  # just keep a latitude, longitude list```Demo```pythonArticle.objects.filter(data__location__near=[39.9, 116.4,5000]) # latitude，longitude，search range```or```pythonArticle.objects.filter(data__location__near='39.9,116.4,5000') # latitude，longitude, search range```**Alert**: if you don't pass exact number of params, this filter will not be used**for more earthdistance**, see [Postgresql Earthdistance Documentation](https://www.postgresql.org/docs/8.3/static/earthdistance.html)------------------------------------------------------------------------------------------------------------------#####For more information about raw jsonb operation, please see [PostgreSQL Documentation](http://www.postgresql.org/docs/9.4/static/functions-json.html)