dblite.api.Transaction Class Reference

Transaction context manager, breakable by raising Rollback. More...

Inheritance diagram for dblite.api.Transaction:

Public Member Functions
def	__init__ (self, db, commit=True, exclusive=False, **kwargs)
	Constructs a new transaction. More...
def	__del__ (self)
	Closes the transaction, if open. More...
def	__enter__ (self)
	Context manager entry, returns Transaction object. More...
def	__exit__ (self, exc_type, exc_val, exc_trace)
	Context manager exit, propagates raised errors except Rollback. More...
def	close (self, commit=None)
	Closes the transaction, performing commit or rollback as specified. More...
def	commit (self)
	Commits pending actions, if any. More...
def	rollback (self)
	Rolls back pending actions, if any. More...
Public Member Functions inherited from dblite.api.Queryable
def	delete (self, table, where=(), **kwargs)
	Convenience wrapper for database DELETE, returns affected row count. More...
def	execute (self, sql, args=())
	Executes the SQL statement and returns database cursor. More...
def	executemany (self, sql, args)
	Executes the SQL statement against all parameter sequences. More...
def	executescript (self, sql)
	Executes the SQL as script of any number of statements. More...
def	fetchall (self, table, cols="*", where=(), group=(), order=(), limit=(), **kwargs)
	Convenience wrapper for database SELECT and fetch all. More...
def	fetchone (self, table, cols="*", where=(), group=(), order=(), limit=(), **kwargs)
	Convenience wrapper for database SELECT and fetch one. More...
def	insert (self, table, values=(), **kwargs)
	Convenience wrapper for database INSERT, returns inserted row ID. More...
def	insertmany (self, table, rows=(), **kwargs)
	Convenience wrapper for database multiple INSERTs, returns list of inserted row IDs. More...
def	makeSQL (self, action, table, cols="*", where=(), group=(), order=(), limit=(), values=(), kwargs=None)
	Returns (SQL statement string, parameter dict). More...
def	quote (cls, value, force=False)
	Returns identifier in quotes and proper-escaped for queries, if value needs quoting (has non-alphanumerics, starts with number, or is reserved). More...
def	select (self, table, cols="*", where=(), group=(), order=(), limit=(), **kwargs)
	Convenience wrapper for database SELECT, returns database cursor. More...
def	update (self, table, values, where=(), **kwargs)
	Convenience wrapper for database UPDATE, returns affected row count. More...

Properties
	database = property
	Returns transaction Database instance. More...
Properties inherited from dblite.api.Queryable
	closed = property
	Whether currently not open. More...
	cursor = property
	Database engine cursor object, or `None` if closed. More...

Additional Inherited Members
Static Public Attributes inherited from dblite.api.Queryable
	ENGINE = None
	Underlying database engine, "sqlite" for SQLite3 and "postgres" for PostgreSQL. More...

Detailed Description

Transaction context manager, breakable by raising Rollback.

Note that in SQLite, a single connection has one shared transaction state, so it is highly recommended to use exclusive Transaction instances for any action queries, as concurrent transactions can interfere with one another otherwise.

Definition at line 450 of file api.py.

Constructor & Destructor Documentation

__init__()

def dblite.api.Transaction.__init__	(		self,
			db,
			commit = True,
			exclusive = False,
		**	kwargs
	)

Constructs a new transaction.

Note that parameter `exclusive` defaults to `True` when using SQLite.

Parameters

db	Database instance
commit	whether transaction commits automatically at exiting with-block
exclusive	whether entering a with-block is exclusive over other Transaction instances on this Database
kwargs	engine-specific arguments, like `schema="other", lazy=True` for Postgres

Reimplemented in dblite.engines.sqlite.Transaction.

Definition at line 463 of file api.py.

__del__()

def dblite.api.Transaction.__del__

(

self

)

Closes the transaction, if open.

Definition at line 474 of file api.py.

Member Function Documentation

__enter__()

def dblite.api.Transaction.__enter__

(

self

)

Context manager entry, returns Transaction object.

Reimplemented in dblite.engines.postgres.Transaction, and dblite.engines.sqlite.Transaction.

Definition at line 466 of file api.py.

__exit__()

def dblite.api.Transaction.__exit__	(		self,
			exc_type,
			exc_val,
			exc_trace
	)

Context manager exit, propagates raised errors except Rollback.

Reimplemented in dblite.engines.postgres.Transaction, and dblite.engines.sqlite.Transaction.

Definition at line 470 of file api.py.

close()

def dblite.api.Transaction.close	(		self,
			commit = None
	)

Closes the transaction, performing commit or rollback as specified.

Required if not using transaction as context manager in a with-block.

Parameters

commit

`True` for explicit commit, `False` for explicit rollback, `None` defaults to `commit` flag from creation

Reimplemented in dblite.engines.postgres.Transaction, and dblite.engines.sqlite.Transaction.

Definition at line 484 of file api.py.

commit()

def dblite.api.Transaction.commit

(

self

)

Commits pending actions, if any.

Reimplemented in dblite.engines.postgres.Transaction, and dblite.engines.sqlite.Transaction.

Definition at line 487 of file api.py.

rollback()

def dblite.api.Transaction.rollback

(

self

)

Rolls back pending actions, if any.

Reimplemented in dblite.engines.postgres.Transaction, and dblite.engines.sqlite.Transaction.

Definition at line 491 of file api.py.

Property Documentation

database

dblite.api.Transaction.database = property

static

Returns transaction Database instance.

Definition at line 497 of file api.py.

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The documentation for this class was generated from the following file:

• dblite/api.py