Extras¶

Miscellaneous helpers for working with psycopg2.

class kirameki.extras.Result(lastrowid, rowcount)¶: A namedtuple() representing the result of a execute() call.

class kirameki.extras.SimpleConnection¶: A class inheriting from connection and SimpleConnectionMixin.

class kirameki.extras.SimpleConnectionMixin¶

A connection mixin providing helper methods.

callproc(procname, parameters=None)¶

Call a single stored procedure without constructing a cursor.

See cursor.callproc().

Returns: an iterator over rows returned by the call.

callproc_one(procname, parameters=None)¶

Call a single stored procedure without constructing a cursor and return a single row.

See cursor.callproc(). Warns when more than one row is returned.

Returns: a single row

execute(query, vars=None)¶

Execute a single query without constructing a cursor.

See cursor.execute().

Returns: a namedtuple providing two fields: lastrowid and rowcount.
Return type: Result

query(query, vars=None)¶

Execute a single query without constructing a cursor.

See cursor.execute().

Returns: an iterator over rows returned by the call.

query_one(query, vars=None)¶

Execute a single query without constructing a cursor.

See cursor.execute(). Warns when more than one row is returned.

Returns: a single row

transaction(isolation_level=None, readonly=None, deferrable=None)¶

Start a transaction context.

See connection.set_session() for more information.

Parameters

isolation_level (Union[str, int], optional) – set session isolation level in this context, default behavior is to not change current isolation level i.e. None
readonly (bool, optional) – make session read-only in this context, default behavior is to not change current read-only state
deferrable (bool, optional) – make session deferrable in this context, default behavior is to not change current deferrable state

Raises

psycopg2.OperationalError – when invalid values are provided or the database state is invalid (e.g. in-transaction)

Returns

a transactional control object that is also a context manager

Return type

Transaction

transaction_class¶

The transaction class.

alias of kirameki.extras.Transaction

class kirameki.extras.Transaction¶

A transaction context manager.

begin()¶: Begin a transaction block. You should only call this method after calling commit() with begin=False.

commit(begin=True)¶

Commit the transaction.

Parameters: begin (bool, optional) – begin a new transaction if this transaction commits successfully, defaults to True

rollback()¶: Rollback the migration.

savepoint(name)¶

Start a savepoint context.

Parameters: name (str) – savepoint name
Returns: a savepoint control object that is also a context manager

savepoint_class¶

The savepoint class to use.

alias of kirameki.extras.Savepoint

class kirameki.extras.Savepoint¶

A savepoint context manager.

begin()¶: Create a savepoint. You should only call this method after calling commit() with begin=False.

commit(begin=True)¶

Release the savepoint.

Parameters: begin (bool, optional) – create a new savepoint if this savepoint is released successfully, defaults to True

rollback()¶: Rollback the savepoint.

savepoint(name)¶

Create a new, nested savepoint of the same type.

Parameters: name (str) – savepoint name

kirameki.extras.set_session(conn, **kwargs)¶

Set session parameters within a context.

This context manager sets given session parameters on enter and restores them to their previous values on exit.

See connection.set_session().