SQLite
JSON1 extension and json_extract (see accepted answer). Example:
import sqlite3, json # tested with precompiled Windows binaries from https://www.sqlite.org/download.html (sqlite3.dll copied in C:\Python37\DLLs)
class sqlitenosql:
def __init__(self, f):
self.db = sqlite3.connect(f)
self.db.execute('CREATE TABLE test(data TEXT);')
def close(self):
self.db.commit()
self.db.close()
def addrow(self, d):
self.db.execute("INSERT INTO test VALUES (?);", (json.dumps(d),))
def find(self, query):
for k, v in query.items():
if isinstance(v, str):
query[k] = f"'{v}'"
q = ' AND '.join(f" json_extract(data, '$.{k}') = {v}" for k, v in query.items())
for r in self.db.execute(f"SELECT * FROM test WHERE {q}"):
yield r[0]
db = sqlitenosql(':memory:')
db.addrow({'name': 'john', 'balance': 1000, 'data': [1, 73.23, 18], 'abc': 'hello'})
db.addrow({'name': 'alice', 'balance': 2000, 'email': 'a@b.com'})
db.addrow({'name': 'bob', 'balance': 1000})
db.addrow({'name': 'richard', 'balance': 1000, 'abc': 'hello'})
for r in db.find({'balance': 1000, 'abc': 'hello'}):
print(r)
# {"name": "john", "balance": 1000, "data": [1, 73.23, 18], "abc": "hello"}
# {"name": "richard", "balance": 1000, "abc": "hello"}
db.close()
sqlitedict as mentioned in Key: value store in Python for possibly 100 GB of data, without client/server and Use SQLite as a key:value store
with:
key = an ID
value = the dict we want to store, e.g. {'name': 'alice', 'balance': 2000, 'email': 'a@b.com'}
Further reading about use of SQLite with JSON: https://community.esri.com/groups/appstudio/blog/2018/08/21/working-with-json-in-sqlite-databases
TinyDB
TinyDB looks like a good solution:
>>> from tinydb import TinyDB, Query
>>> db = TinyDB('path/to/db.json')
>>> User = Query()
>>> db.insert({'name': 'John', 'age': 22})
>>> db.search(User.name == 'John')
[{'name': 'John', 'age': 22}]
However, the documentation mentions that it's not the right tool if we need:
- access from multiple processes or threads,
- creating indexes for tables,
- an HTTP server,
- managing relationships between tables or similar,
- ACID guarantees
So it's a half solution :)
Oher solutions
Seems interesting too : WhiteDB
