Welcome to TinyDB!¶

Welcome to TinyDB, your tiny, document oriented database optimized for your happiness :)

>>> from tinydb import TinyDB, where
>>> db = TinyDB('path/to/db.json')
>>> db.insert({'int': 1, 'char': 'a'})
>>> db.search(where('int') == 1)
[{'int': 1, 'char': 'a'}]

User’s Guide¶

Introduction¶

Great that you’ve taken time to check out the TinyDB docs! Before we begin looking at TinyDB itself, let’s take some time to see whether you should use TinyDB.

Why using TinyDB?¶

tiny: The current source code has 1200 lines of code (+ 600 lines tests). For comparison: Buzhug has about 2000 lines of code (w/o tests), CodernityDB has about 8000 lines of code (w/o tests).
document oriented: Like MongoDB, you can store any document (represented as dict) in TinyDB.
optimized for your happiness: TinyDB is designed to be simple and fun to use by providing a simple and clean API.
written in pure Python: TinyDB neither needs an external server (as e.g. PyMongo) nor any dependencies from PyPI.
works on Python 2.6 – 3.4 and PyPy: TinyDB works on all modern versions of Python and PyPy.
easily extensible: You can easily extend TinyDB by writing new storages or modify the behaviour of storages with Middlewares.
nearly 100% test coverage: If you don’t count that __repr__ methods and some abstract methods are not tested, TinyDB has a test coverage of 100%.

In short: If you need a simple database with a clean API that just works without lots of configuration, TinyDB might be the right choice for you.

Why not using TinyDB?¶

You need advanced features like multiple indexes, an HTTP server, relationships, or similar.
You are really concerned about high performance and need a high speed database.

To put it plainly: If you need advanced features or high performance, TinyDB is the wrong database for you – consider using databases like Buzhug, CodernityDB or MongoDB.

Getting Started¶

Installing TinyDB¶

To install TinyDB from PyPI, run:

$ pip install tinydb

You can also grab the latest development version from GitHub. After downloading and unpacking it, you can install it using:

$ python setup.py install

Basic Usage¶

Let’s cover the basics before going more into detail. We’ll start by setting up a TinyDB database:

>>> from tinydb import TinyDB, where
>>> db = TinyDB('db.json')

You now have a TinyDB database that stores its data in db.json. What about inserting some data? TinyDB expects the data to be Python dicts:

>>> db.insert({'type': 'apple', 'count': 7})
1
>>> db.insert({'type': 'peach', 'count': 3})
2

Note

The insert method returns the inserted element’s ID. Read more about it here: Using Element IDs.

Now you can get all elements stored in the database by running:

>>> db.all()
[{'count': 7, 'type': 'apple'}, {'count': 3, 'type': 'peach'}]

Of course you’ll also want to search for specific elements. Let’s try:

>>> db.search(where('type') == 'peach')
[{'count': 3, 'type': 'peach'}]
>>> db.search(where('count') > 5)
[{'count': 7, 'type': 'apple'}]

Next we’ll update the count field of the apples:

>>> db.update({'count': 10}, where('type') == 'apple')
>>> db.all()
[{'count': 10, 'type': 'apple'}, {'count': 3, 'type': 'peach'}]

In the same manner you can also remove elements:

>>> db.remove(where('count') < 5)
>>> db.all()
[{'count': 10, 'type': 'apple'}]

And of course you can throw away all data to start with an empty database:

>>> db.purge()
>>> db.all()
[]

Recap¶

Before we dive deeper, let’s recapitulate the basics:

Inserting
`db.insert(...)`	Insert an element
Getting data
`db.all()`	Get all elements
`db.search(query)`	Get a list of elements matching the query
Updating
`db.update(fields, query)`	Update all elements matching the query to contain `fields`
Removing
`db.remove(query)`	Remove all elements matching the query
`db.purge()`	Purge all elements
Querying
`where('field') == 2`	Match any element that has a key `field` with value `== 2` (also possible: `!=` `>` `>=` `<` `<=`)

Advanced Usage¶

Remarks on Serialization¶

Before we dive deeper into the usage of TinyDB, we should stop for a moment and discuss the topic of serializtion.

TinyDB serializes all data using the Python JSON module by default. It’s great for serializing simple data types but cannot handle more complex data types like custom classes. On Python 2 it also converts strings to unicode strings upon reading (described here).

If you need a better serializer, you can write your own storage, that uses a more powerful (but also slower) library like pickle or PyYAML.

Alternative JSON libary¶

As already mentioned, the default default storage serializes the data using JSON. To improve performance, you can install ujson , an extremely fast JSON implementation. TinyDB will auto-detect and use it if possible.

Handling Data¶

So let’s start with inserting and retrieving data from your database.

Inserting¶

As already described you can insert an element using db.insert(...). In case you want to insert multiple elements, you can use db.insert_multiple(...):

>>> db.insert_multiple([{'int': 1, 'char': 'a'}, {'int': 1, 'char': 'b'}])
>>> db.insert_multiple({'int': 1, 'value': i} for i in range(2))

Retrieving¶

There are several ways to retrieve data from your database. For instance you can get the number of stored elements:

>>> len(db)
3

Then of course you can use db.search(...) as described in the Getting Started section. But sometimes you want to get only one matching element. Instead of using

>>> try:
...     result = db.search(where('value') == 1)[0]
... except IndexError:
...     pass

you can use db.get(...):

>>> db.get(where('value') == 1)
{'int': 1, 'value': 1}
>>> db.get(where('value') == 100)
None

Caution

If multiple elements match the query, propably a random one of them will be returned!

Often you don’t want to search for elements but only know whether they are stored in the database. In this case db.contains(...) is your friend:

>>> db.contains(where('char') == 'a')

In a similar manner you can look up the number of elements matching a query:

>>> db.count(where('int') == 1)
3

Recap¶

Let’s summarize the ways to handle data:

Inserting
`db.insert_multiple(...)`	Insert multiple elements
Getting data
`len(db)`	Get the number of elements in the database
`db.get(query)`	Get one element matching the query
`db.contains(query)`	Check if the database contains a matching element
`db.count(query)`	Get the number of matching elements

Using Element IDs¶

Internally TinyDB associates an ID with every element you insert. It’s returned after inserting an element:

>>> db.insert({'value': 1})
3
>>> db.insert_multiple([{...}, {...}, {...}])
[4, 5, 6]

In addition you can get the ID of already inserted elements using element.eid:

>>> el = db.get(where('value') == 1)
>>> el.eid
3

Different TinyDB methods also work with IDs, namely: update, remove, contains and get.

>>> db.update({'value': 2}, eids=[1, 2])
>>> db.contains(eids=[1])
True
>>> db.remove(eids=[1, 2])
>>> db.get(eid=3)
{...}

Recap¶

Let’s sum up the way TinyDB supports working with IDs:

Getting an element’s ID
`db.insert(...)`	Returns the inserted element’s ID
`db.insert_multiple(...)`	Returns the inserted elements’ ID
`element.eid`	Get the ID of an element fetched from the db
Working with IDs
`db.get(eid=...)`	Get the elemtent with the given ID
`db.contains(eids=[...])`	Check if the db contains elements with one of the given IDs
`db.update({...}, eids=[...])`	Update all elements with the given IDs
`db.remove(eids=[...])`	Remove all elements with the given IDs

Queries¶

TinyDB lets you use a rich set of queries. In the Getting Started you’ve learned about the basic comparisons (==, <, >, ...). In addition to that TinyDB enables you run logical operations on queries.

>>> # Negate a query:
>>> db.search(~ where('int') == 1)

>>> # Logical AND:
>>> db.search((where('int') == 1) & (where('char') == 'b'))
[{'int': 1, 'char': 'b'}]

>>> # Logical OR:
>>> db.search((where('char') == 'a') | (where('char') == 'b'))
[{'int': 1, 'char': 'a'}, {'int': 1, 'char': 'b'}]

Note

When using & or |, make sure you wrap the conditions on both sides with parentheses or Python will mess up the comparison.

You also can search for elements where a specific key exists:

>>> db.search(where('char'))
[{'int': 1, 'char': 'a'}, {'int': 1, 'char': 'b'}]

Advanced queries¶

In addition to these checks TinyDB supports checking against a regex or a custom test function:

>>> # Regex:
>>> db.search(where('char').matches('[aZ]*'))
[{'int': 1, 'char': 'a'}, {'int': 1, 'char': 'b'}]

>>> # Custom test:
>>> test_func = lambda c: c == 'a'
>>> db.search(where('char').test(test_func))
[{'char': 'a', 'int': 1}]

Nested Queries¶

You can insert nested elements into your database:

>>> db.insert({'field': {'name': {'first_name': 'John', 'last_name': 'Doe'}}})

To search for a nested field, use where('field').has(...). You can apply any queries you already know to this selector:

>>> db.search(where('field').has('name'))
[{'field': ...}]
>>> db.search(where('field').has('name').has('last_name') == 'Doe')
[{'field': ...}]

You also can use lists inside of elements:

>>> db.insert({'field': [{'val': 1}, {'val': 2}, {'val': 3}])

Using where('field').any(...) and where('field').all(...) you can specify checks for the list’s items. They behave similarly to Python’s any and all:

>>> db.search(where('field').any(where('val') == 1))
True
>>> db.search(where('field').all(where('val') > 0))
True

Recap¶

Again, let’s recapitulate the query operations:

Queries
`where('field').matches(regex)`	Match any element matching the regular expression
`where('field').test(func)`	Matches any element for which the function returns `True`
Combining Queries
`~ query`	Match elements that don’t match the query
`(query1) & (query2)`	Match elements that match both queries
`(query1) \| (query2)`	Match elements that match one of the queries
Nested Queries
`where('field').has('field')`	Match any element that has the specified item. Perform more queries on this selector as needed
`where('field').any(query)`	Match any element where ‘field’ is a list where one of the items matches the subquery
`where('field').all(query)`	Match any element where ‘field’ is a list where all items match the subquery

Tables¶

TinyDB supports working with multiple tables. They behave just the same as the TinyDB class. To create and use a table, use db.table(name).

>>> table = db.table('table_name')
>>> table.insert({'value': True})
>>> table.all()
[{'value': True}]

To remove all tables from a database, use:

>>> db.purge_tables()

Note

TinyDB uses a table named _default as default table. All operations on the database object (like db.insert(...)) operate on this table.

You can get a list with the names of all tables in your database:

>>> db.tables()
{'_default', 'table_name'}

Query Caching¶

TinyDB caches query result for performance. You can optimize the query cache size by passing the cache_size to the table(...) function:

>>> table = db.table('table_name', cache_size=30)

Hint

You can set cache_size to None to make the cache unlimited in size.

Smart Query Cache¶

If you perform lots of queries while the data changes only little, you may enable a smarter query cache. It updates the query cache when inserting/removing/updating elements so the cache doesn’t get invalidated.

>>> table = db.table('table_name', smart_cache=True)

Storages & Middlewares¶

Storage Types¶

TinyDB comes with two storage types: JSON and in-memory. By default TinyDB stores its data in JSON files so you have to specify the path where to store it:

>>> from tinydb import TinyDB, where
>>> db = TinyDB('path/to/db.json')

To use the in-memory storage, use:

>>> from tinydb.storages import MemoryStorage
>>> db = TinyDB(storage=MemoryStorage)

Middlewares¶

Middlewares wrap around existing storages allowing you to customize their behaviour.

>>> from tinydb.storages import JSONStorage
>>> from tinydb.middlewares import CachingMiddleware
>>> db = TinyDB('/path/to/db.json', storage=CachingMiddleware(JSONStorage))

Hint

You can nest middlewares:

>>> db = TinyDB('/path/to/db.json', storage=FirstMiddleware(SecondMiddleware(JSONStorage)))

CachingMiddleware¶

The CachingMiddleware improves speed by reducing disk I/O. It caches all read operations and writes data to disk after a configured number of write operations.

To make sure that all data is safely written when closing the table, use one of these ways:

# Using a context manager:
with database as db:
    # Your operations

# Using the close function
db.close()

Contribution Guidelines¶

Whether reporting bugs, discussing improvements and new ideas or writing extensions: Contributions to TinyDB are welcome! Here’s how to get started:

Check for open issues or open a fresh issue to start a discussion around a feature idea or a bug
Fork the repository on Github, create a new branch off the master branch and start making your changes (known as GitHub Flow)
Write a test which shows that the bug was fixed or that the feature works as expected
Send a pull request and bug the maintainer until it gets merged and published :)

Philosophy of TinyDB¶

TinyDB aims to be simple and fun to use. Therefore two key values in development are simplicity and elegance. Sometimes these values contradict each other. In this case, try using as little magic as possible. In any case don’t forget commenting code that isn’t clear at first glance.

Code Conventions¶

In general the TinyDB source should always follow PEP 8. Exceptions are allowed in well justified and documented cases. However we make a small exception concerning docstrings:

When using multiline docstrings, keep the opening and closing triple quotes on their own lines and add an empty line after it.

def some_function():
    """
    Documentation ...
    """

    # implementation ...

Version Numbers¶

TinyDB follows the SemVer versioning guidelines. This implies that backwards incompatible changes in the API will increment the major version. So think twice before making such changes.

Extending TinyDB¶

How to Extend TinyDB¶

Write a custom Storage¶

You can write a custom storage by subclassing Storage:

class CustomStorage(Storage):
    def __init__(self, arg1):
        pass

    def read(self):
        # your implementation

    def write(self, data):
        # your implementation

    def close(self):
        # optional: close open file handles, etc.

To indicate that your storage is empty, raise an ValueError in read(self). TinyDB will create the data for a new database and ask your storage to write it.

When creating a new instance of TinyDB, the instance will pass all arguments and keyword arguments (except storage) to your storage class:

db = TinyDB(arg1, storage=CustomStorage)

Write a custom Middleware¶

You can modify the behaviour of existing storages by writing a custom middleware. To do so, subclass Middleware:

class CustomMiddleware(CustomMiddleware):
    def __init__(self, storage_cls):
        # Any middleware *has* to call the super constructor
        # with storage_cls
        super(CustomMiddleware, self).__init__(storage_cls)

    def read(self):
        # your implementation
        self.storage.read()  # access the storage's read function

    def write(self, data):
        # your implementation
        self.storage.write(data)  # access the storage's close function

    def close(self):
        # optional: close open file handles, etc.
        self.storage.close()  # access the storage's close function

Remember to call the super constructor in your __init__ as shown in the example.

To wrap a storage with your new middleware, use

db = TinyDB(storage=CustomMiddleware(SomeStorageClass))

Extensions¶

`tinyrecord`¶

Repo:        https://github.com/eugene-eeo/tinyrecord
Status:      experimental
Description: Tinyrecord is a library which implements experimental atomic
transaction support for the TinyDB NoSQL database. It uses a
record-first then execute architecture which allows us to
minimize the time that we are within a thread lock.

API Reference¶

API Documentation¶

`tinydb.database`¶

class tinydb.database.TinyDB(*args, **kwargs)¶

The main class of TinyDB.

Gives access to the database, provides methods to insert/search/remove and getting tables.

__enter__()¶: See Table.__enter__()

__exit__(*args)¶: See Table.__exit__()

__getattr__(name)¶: Forward all unknown attribute calls to the underlying standard table.

__init__(*args, **kwargs)¶

Create a new instance of TinyDB.

All arguments and keyword arguments will be passed to the underlying storage class (default: JSONStorage).

Parameters:	storage – The class of the storage to use. Will be initialized with `args` and `kwargs`.

__len__()¶

Get the total number of elements in the DB.

>>> len(db)
0

purge_tables()¶: Purge all tables from the database. CANNOT BE REVERSED!

table(name='_default', smart_cache=False, **options)¶

Get access to a specific table.

Creates a new table, if it hasn’t been created before, otherwise it returns the cached Table object.

Parameters:	name (str) – The name of the table. smart_cache – Use a smarter query caching. See `tinydb.database.SmartCacheTable` cache_size – How many query results to cache.

tables()¶

Get the names of all tables in the database.

Returns:	a set of table names
Return type:	set[str]

class tinydb.database.Table(name, db, cache_size=10)¶

Represents a single TinyDB Table.

__enter__()¶

Allow the database to be used as a context manager.

Returns:	the table instance

__exit__(*args)¶: Try to close the storage after being used as a context manager.

__init__(name, db, cache_size=10)¶

Get access to a table.

Parameters:	name (str) – The name of the table. db (tinydb.database.TinyDB) – The parent database. cache_size – Maximum size of query cache.

__len__()¶: Get the total number of elements in the table.

all()¶

Get all elements stored in the table.

Returns:	a list with all elements.
Return type:	list[Element]

close(*args)¶: Try to close the storage after being used as a context manager.

contains(cond=None, eids=None)¶

Check wether the database contains an element matching a condition or an ID.

If eids is set, it checks if the db contains an element with one of the specified.

Parameters:	cond (Query) – the condition use eids – the element IDs to look for

count(cond)¶

Count the elements matching a condition.

Parameters:	cond (Query) – the condition use

get(cond=None, eid=None)¶

Get exactly one element specified by a query or and ID.

Returns None if the element doesn’t exist

Parameters:	cond (Query) – the condition to check against eid – the element’s ID
Returns:	the element or None
Return type:	Element \| None

insert(element)¶

Insert a new element into the table.

Parameters:	element – the element to insert
Returns:	the inserted element’s ID

insert_multiple(elements)¶

Insert multiple elements into the table.

Parameters:	elements – a list of elements to insert
Returns:	a list containing the inserted elements’ IDs

process_elements(func, cond=None, eids=None)¶

Helper function for processing all elements specified by condition or IDs.

A repeating pattern in TinyDB is to run some code on all elements that match a condition or are specified by their ID. This is implemented in this function. The function passed as func has to be a callable. It’s first argument will be the data currently in the database. It’s second argument is the element ID of the currently processed element.

See: update(), remove()

Parameters:	func – the function to execute on every included element. first argument: all data second argument: the current eid cond – elements to use eids – elements to use

purge()¶: Purge the table by removing all elements.

remove(cond=None, eids=None)¶

Remove all matching elements.

Parameters:	cond (query) – the condition to check against eids (list) – a list of element IDs

search(cond)¶

Search for all elements matching a ‘where’ cond.

Parameters:	cond (Query) – the condition to check against
Returns:	list of matching elements
Return type:	list[Element]

update(fields, cond=None, eids=None)¶

Update all matching elements to have a given set of fields.

Parameters:	fields (dict) – the fields that the matching elements will have cond (query) – which elements to update eids (list) – a list of element IDs

class tinydb.database.SmartCacheTable(name, db, cache_size=10)¶

A Table with a smarter query cache.

Provides the same methods as Table.

The query cache gets updated on insert/update/remove. Useful when in cases where many searches are done but data isn’t changed often.

class tinydb.database.Element(value=None, eid=None, **kwargs)¶

Represents an element stored in the database.

This is a transparent proxy for database elements. It exists to provide a way to access an element’s id via el.eid.

eid¶: The element’s id

`tinydb.queries`¶

class tinydb.queries.Query(key)¶

Provides methods to do tests on dict fields.

Any type of comparison will be called in this class. In addition, it is aliased to where to provide a more intuitive syntax.

When not using any comparison operation, this simply tests for existence of the given key.

__and__(other)¶

Combines this query and another with logical and.

Example:

>>> (where('f1') == 5) & (where('f2') != 2)
('f1' == 5) and ('f2' != 2)

Return type:	QueryAnd

__call__(element)¶

Run the test on the element.

Parameters:	element (dict) – The dict that we will run our tests against.

__eq__(other)¶

Test a dict value for equality.

>>> where('f1') == 42
'f1' == 42

__ge__(other)¶

Test a dict value for being greater than or equal to another value.

>>> where('f1') >= 42
'f1' >= 42

__gt__(other)¶

Test a dict value for being greater than another value.

>>> where('f1') > 42
'f1' > 42

__invert__()¶

Negates a query.

>>> ~(where('f1') >= 42)
not ('f1' >= 42)

Return type:	tinydb.queries.QueryNot

__le__(other)¶

Test a dict value for being lower than or equal to another value.

>>> where('f1') <= 42
'f1' <= 42

__lt__(other)¶

Test a dict value for being lower than another value.

>>> where('f1') < 42
'f1' < 42

__ne__(other)¶

Test a dict value for inequality.

>>> where('f1') != 42
'f1' != 42

__or__(other)¶

Combines this query and another with logical or.

Example:

>>> (where('f1') == 5) | (where('f2') != 2)
('f1' == 5) or ('f2' != 2)

Return type:	QueryOr

all(cond)¶

Checks if a condition is met by any element in a list.

>>> where('f1').all(where('f2') == 1)
'f1' all have 'f2' == 1

Matches:

{'f1': [{'f2': 1}, {'f2': 1}]}

Parameters:	cond – The condition to check
Return type:	tinydb.queries.Query

any(cond)¶

Checks if a condition is met by any element in a list.

>>> where('f1').any(where('f2') == 1)
'f1' has any 'f2' == 1

Matches:

{'f1': [{'f2': 1}, {'f2': 0}]}

Parameters:	cond – The condition to check
Return type:	tinydb.queries.Query

has(key)¶

Run test on a nested dict.

>>> where('x').has('y') == 2
has 'x' => ('y' == 2)

Matches:

{'x': {'y': 2}}

Parameters:	key – the key to search for in the nested dict
Return type:	QueryHas

matches(regex)¶

Run a regex test against a dict value.

>>> where('f1').matches('^\w+$')
'f1' ~= ^\w+$

Parameters:	regex – The regular expression to pass to `re.match`
Return type:	QueryRegex

test(func)¶

Run a user-defined test function against a dict value.

>>> def test_func(val):
...     return val == 42
...
>>> where('f1').test(test_func)
'f1'.test(<function test_func at 0xXXXXXXXX>)

Parameters:	func – The function to run. Has to accept one parameter and return a boolean.
Return type:	QueryCustom

`tinydb.storage`¶

Contains the base class for storages and implementations.

class tinydb.storages.Storage¶

The abstract base class for all Storages.

A Storage (de)serializes the current state of the database and stores it in some place (memory, file on disk, ...).

read()¶: Read the last stored state.

write(data)¶: Write the current state of the database to the storage.

close()¶: Optional: Close open file handles, etc.

class tinydb.storages.JSONStorage(path)¶

Store the data in a JSON file.

__init__(path)¶

Create a new instance.

Also creates the storage file, if it doesn’t exist.

Parameters:	path (str) – Where to store the JSON data.

class tinydb.storages.MemoryStorage¶

Store the data as JSON in memory.

__init__()¶: Create a new instance.

`tinydb.middlewares`¶

Contains the base class for middlewares and implementations.

class tinydb.middlewares.Middleware¶

The base class for all Middlewares.

Middlewares hook into the read/write process of TinyDB allowing you to extend the behaviour by adding caching, logging, ...

If read() or write() are not overloaded, they will be forwarded directly to the storage instance.

storage¶

Type:	`Storage`

Access to the underlying storage instance.

read()¶: Read the last stored state.

write(data)¶: Write the current state of the database to the storage.

close()¶: Optional: Close open file handles, etc.

class tinydb.middlewares.CachingMiddleware(storage_cls)¶

Add some caching to TinyDB.

This Middleware aims to improve the performance of TinyDB by writing only the last DB state every WRITE_CACHE_SIZE time and reading always from cache.

flush()¶: Flush all unwritten data to disk.

Additional Notes¶

Changelog¶

Version Numbering¶

TinyDB follows the SemVer versioning guidelines. For more information, see semver.org

v2.0.1 (2014-09-22)¶

Fixed handling of unicode data in Python 2 (see issue #28).

v2.0.0 (2014-09-05)¶

Upgrade Notes

Warning

TinyDB changed the way data is stored. You may need to migrate your databases to the new scheme. Check out the Upgrade Notes for details.

The syntax query in db has been removed, use db.contains instead.
The ConcurrencyMiddleware has been removed due to a insecure implementation (see Issue #18). Consider tinyrecord instead.
Better support for working with Element IDs.
Added support for nested comparisons.
Added all and any comparisons on lists.
Added optional smart query caching.
The query cache is now a fixed size lru cache.

v1.4.0 (2014-07-22)¶

Added insert_multiple function (see issue #8).

v1.3.0 (2014-07-02)¶

Fixed bug #7: IDs not unique.
Extended the API: db.count(where(...)) and db.contains(where(...)).
The syntax query in db is now deprecated and replaced by db.contains.

v1.2.0 (2014-06-19)¶

Added update method (see Issue #6).

v1.1.1 (2014-06-14)¶

Merged PR #5: Fix minor documentation typos and style issues.

v1.1.0 (2014-05-06)¶

Improved the docs and fixed some typos.
Refactored some internal code.
Fixed a bug with multiple TinyDB? instances.

v1.0.1 (2014-04-26)¶

Fixed a bug in JSONStorage that broke the database when removing entries.

v1.0.0 (2013-07-20)¶

First official release – consider TinyDB stable now.

Upgrading to Newer Releases¶

Version 2.0¶

Breaking API Changes¶

The syntax query in db is not supported any more. Use db.contains(...) instead.
The ConcurrencyMiddleware has been removed due to a insecure implementation (see Issue #18). Consider tinyrecord instead.

Apart from that the API remains compatible to v1.4 and prior.

Migration¶

To improve the handling of IDs TinyDB changed the way it stores data (see Issue #13 for details). Opening an database from v1.4 or prior will most likely result in an exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "tinydb\database.py", line 49, in __init__
    self._table = self.table('_default')
  File "tinydb\database.py", line 69, in table
    table = table_class(name, self, **options)
  File "tinydb\database.py", line 171, in __init__
    self._last_id = int(sorted(self._read().keys())[-1])
  File "tinydb\database.py", line 212, in _read
    data[eid] = Element(data[eid], eid)
TypeError: list indices must be integers, not dict

In this case you need to migrate the database to the recent scheme. TinyDB provides a migration script for the default JSON storage:

$ python -m tinydb.migrate db1.json db2.json
Processing db1.json ... Done
Processing db2.json ... Done

Migration with a custom storage¶

If you have database files that have been written using a custom storage class, you can write your own migration script that calls tinydb.migrate.migrate:

tinydb.migrate.migrate(*args, **kwargs)¶

Migrate a database to the scheme used in v2.0.

To migrate a db that uses a custom storage, use

>>> from tinydb.migrate import migrate
>>> args = [...]  # args for your storage class
>>> kwargs = {...}  # kwargs for your storage class
>>> migrate(*args, **kwargs, storage=YourStorageClass)
True

Parameters:	storage – The class of the storage to use. Will be initialized with `args` and `kwargs`. Default: `JSONStorage`
Returns:	`True` if the db has been migrated, `False` if the db didn’t need a migration.

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v1.0.1 (2014-04-26)¶

v1.0.0 (2013-07-20)¶

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Migration with a custom storage¶

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