Package gmisclib :: Module sqlbase :: Class DB

Class DB

Base class for all persistent objects in a sqlite database. Not the normal API. Derived classes need to define a write() method.

Nested Classes
	__metaclass__ This is used by all the SQL classes, and initializes the class.

Instance Methods

__init__(self, connection)
x.__init__(...) initializes x; see help(type(x)) for signature

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int

write(self)
This method writes an instance out to its database.

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make_dirty(self)
Changes to an instance are not written to the database unless you call make_dirty() or write().

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is_dirty(self)

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__del__(self)

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Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__, __subclasshook__

Class Methods

bump_id(cls, delta)
You can call this manually if you want to introduce a gap between ID numbers.

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None

confirm(cls, connection)
This can be called to confirm that the column names in the database matches what the class expects.

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None

create(cls, connection, if_not_exists=True)
This creates the table in the database.

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set_ID(cls, connection)
This should be called when you first open an existing database when you have the intent to write.

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index_unique(cls, connection, *columns)

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index_nonunique(cls, connection, *columns)

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flush_cache(cls)

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Class Variables
	S_notinDB = `0`
	S_inDB = `1`
	S_modified = `2`
	SQL_name = `'DB'`
	idx = `0`

Properties
Inherited from `object`: `__class__`

Method Details

init(self, connection)
(Constructor)

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x.__init__(...) initializes x; see help(type(x)) for signature

Parameters:

connection (sqlite3.Connection)

Overrides: object.__init__

write(self)

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This method writes an instance out to its database. This method should assemble its attributes to form an argument list for _write, and then call _write with that argument list. It should be used like this:

       def write(self):
               return self._write(self.something, self.other, self.stuff, self.misc)

Returns: int: the return value of _write.

Notes:

write() forces an immediate write or an update of the database, whether or not you have called make_dirty(). make_dirty() simply arranges for a write to occur when the object is eventually destroyed.
The instance remembers the database from which it came.
Do not pass self.id to self._write(). That's handled automatically.

make_dirty(self)

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Changes to an instance are not written to the database unless you call make_dirty() or write(). write() forces an immediate write, whereas make_dirty() simply marks the instance so that it will eventually be written out when the destructor is called.

Note: Global variables are destroyed very late, possibly after other necessary objects have already been destroyed, so you may not want to trust that make_Dirty() will behave well on global variables.

confirm(cls, connection)
Class Method

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This can be called to confirm that the column names in the database matches what the class expects.

Parameters:

connection (sqlite3.Connection) - A connection to a database.

Returns: None

None

Raises:

ColumnMismatchError - When something is wrong.
NoSuchTable - when the table doesn't exist.

create(cls, connection, if_not_exists=True)
Class Method

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This creates the table in the database. It is harmless if the table already exists.

Parameters:

connection (sqlite3.Connection) - A connection to a database.

Returns: None

None

set_ID(cls, connection)
Class Method

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This should be called when you first open an existing database when you have the intent to write. It sets the initial ID number to be larger than the largest ID in the database.

Class DB

__init__(self, connection) (Constructor)

write(self)

make_dirty(self)

confirm(cls, connection) Class Method

create(cls, connection, if_not_exists=True) Class Method

set_ID(cls, connection) Class Method

init(self, connection)
(Constructor)

confirm(cls, connection)
Class Method

create(cls, connection, if_not_exists=True)
Class Method

set_ID(cls, connection)
Class Method