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lib/python3.4/site-packages/sqlalchemy/dialects/sqlite/__init__.py

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+# sqlite/__init__.py
+# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+
+from sqlalchemy.dialects.sqlite import base, pysqlite
+
+# default dialect
+base.dialect = pysqlite.dialect
+
+from sqlalchemy.dialects.sqlite.base import (
+    BLOB, BOOLEAN, CHAR, DATE, DATETIME, DECIMAL, FLOAT, INTEGER, REAL,
+    NUMERIC, SMALLINT, TEXT, TIME, TIMESTAMP, VARCHAR, dialect,
+)
+
+__all__ = ('BLOB', 'BOOLEAN', 'CHAR', 'DATE', 'DATETIME', 'DECIMAL',
+           'FLOAT', 'INTEGER', 'NUMERIC', 'SMALLINT', 'TEXT', 'TIME',
+           'TIMESTAMP', 'VARCHAR', 'REAL', 'dialect')

lib/python3.4/site-packages/sqlalchemy/dialects/sqlite/pysqlite.py

@@ -0,0 +1,339 @@
+# sqlite/pysqlite.py
+# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: http://www.opensource.org/licenses/mit-license.php
+
+"""
+.. dialect:: sqlite+pysqlite
+    :name: pysqlite
+    :dbapi: sqlite3
+    :connectstring: sqlite+pysqlite:///file_path
+    :url: http://docs.python.org/library/sqlite3.html
+
+    Note that ``pysqlite`` is the same driver as the ``sqlite3``
+    module included with the Python distribution.
+
+Driver
+------
+
+When using Python 2.5 and above, the built in ``sqlite3`` driver is
+already installed and no additional installation is needed.  Otherwise,
+the ``pysqlite2`` driver needs to be present.  This is the same driver as
+``sqlite3``, just with a different name.
+
+The ``pysqlite2`` driver will be loaded first, and if not found, ``sqlite3``
+is loaded.  This allows an explicitly installed pysqlite driver to take
+precedence over the built in one.   As with all dialects, a specific
+DBAPI module may be provided to :func:`~sqlalchemy.create_engine()` to control
+this explicitly::
+
+    from sqlite3 import dbapi2 as sqlite
+    e = create_engine('sqlite+pysqlite:///file.db', module=sqlite)
+
+
+Connect Strings
+---------------
+
+The file specification for the SQLite database is taken as the "database"
+portion of the URL.  Note that the format of a SQLAlchemy url is::
+
+    driver://user:pass@host/database
+
+This means that the actual filename to be used starts with the characters to
+the **right** of the third slash.   So connecting to a relative filepath
+looks like::
+
+    # relative path
+    e = create_engine('sqlite:///path/to/database.db')
+
+An absolute path, which is denoted by starting with a slash, means you
+need **four** slashes::
+
+    # absolute path
+    e = create_engine('sqlite:////path/to/database.db')
+
+To use a Windows path, regular drive specifications and backslashes can be
+used. Double backslashes are probably needed::
+
+    # absolute path on Windows
+    e = create_engine('sqlite:///C:\\\\path\\\\to\\\\database.db')
+
+The sqlite ``:memory:`` identifier is the default if no filepath is
+present.  Specify ``sqlite://`` and nothing else::
+
+    # in-memory database
+    e = create_engine('sqlite://')
+
+Compatibility with sqlite3 "native" date and datetime types
+-----------------------------------------------------------
+
+The pysqlite driver includes the sqlite3.PARSE_DECLTYPES and
+sqlite3.PARSE_COLNAMES options, which have the effect of any column
+or expression explicitly cast as "date" or "timestamp" will be converted
+to a Python date or datetime object.  The date and datetime types provided
+with the pysqlite dialect are not currently compatible with these options,
+since they render the ISO date/datetime including microseconds, which
+pysqlite's driver does not.   Additionally, SQLAlchemy does not at
+this time automatically render the "cast" syntax required for the
+freestanding functions "current_timestamp" and "current_date" to return
+datetime/date types natively.   Unfortunately, pysqlite
+does not provide the standard DBAPI types in ``cursor.description``,
+leaving SQLAlchemy with no way to detect these types on the fly
+without expensive per-row type checks.
+
+Keeping in mind that pysqlite's parsing option is not recommended,
+nor should be necessary, for use with SQLAlchemy, usage of PARSE_DECLTYPES
+can be forced if one configures "native_datetime=True" on create_engine()::
+
+    engine = create_engine('sqlite://',
+        connect_args={'detect_types':
+            sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES},
+        native_datetime=True
+    )
+
+With this flag enabled, the DATE and TIMESTAMP types (but note - not the
+DATETIME or TIME types...confused yet ?) will not perform any bind parameter
+or result processing. Execution of "func.current_date()" will return a string.
+"func.current_timestamp()" is registered as returning a DATETIME type in
+SQLAlchemy, so this function still receives SQLAlchemy-level result
+processing.
+
+.. _pysqlite_threading_pooling:
+
+Threading/Pooling Behavior
+---------------------------
+
+Pysqlite's default behavior is to prohibit the usage of a single connection
+in more than one thread.   This is originally intended to work with older
+versions of SQLite that did not support multithreaded operation under
+various circumstances.  In particular, older SQLite versions
+did not allow a ``:memory:`` database to be used in multiple threads
+under any circumstances.
+
+Pysqlite does include a now-undocumented flag known as
+``check_same_thread`` which will disable this check, however note that
+pysqlite connections are still not safe to use in concurrently in multiple
+threads.  In particular, any statement execution calls would need to be
+externally mutexed, as Pysqlite does not provide for thread-safe propagation
+of error messages among other things.   So while even ``:memory:`` databases
+can be shared among threads in modern SQLite, Pysqlite doesn't provide enough
+thread-safety to make this usage worth it.
+
+SQLAlchemy sets up pooling to work with Pysqlite's default behavior:
+
+* When a ``:memory:`` SQLite database is specified, the dialect by default
+  will use :class:`.SingletonThreadPool`. This pool maintains a single
+  connection per thread, so that all access to the engine within the current
+  thread use the same ``:memory:`` database - other threads would access a
+  different ``:memory:`` database.
+* When a file-based database is specified, the dialect will use
+  :class:`.NullPool` as the source of connections. This pool closes and
+  discards connections which are returned to the pool immediately. SQLite
+  file-based connections have extremely low overhead, so pooling is not
+  necessary. The scheme also prevents a connection from being used again in
+  a different thread and works best with SQLite's coarse-grained file locking.
+
+  .. versionchanged:: 0.7
+      Default selection of :class:`.NullPool` for SQLite file-based databases.
+      Previous versions select :class:`.SingletonThreadPool` by
+      default for all SQLite databases.
+
+
+Using a Memory Database in Multiple Threads
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+To use a ``:memory:`` database in a multithreaded scenario, the same
+connection object must be shared among threads, since the database exists
+only within the scope of that connection.   The
+:class:`.StaticPool` implementation will maintain a single connection
+globally, and the ``check_same_thread`` flag can be passed to Pysqlite
+as ``False``::
+
+    from sqlalchemy.pool import StaticPool
+    engine = create_engine('sqlite://',
+                        connect_args={'check_same_thread':False},
+                        poolclass=StaticPool)
+
+Note that using a ``:memory:`` database in multiple threads requires a recent
+version of SQLite.
+
+Using Temporary Tables with SQLite
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Due to the way SQLite deals with temporary tables, if you wish to use a
+temporary table in a file-based SQLite database across multiple checkouts
+from the connection pool, such as when using an ORM :class:`.Session` where
+the temporary table should continue to remain after :meth:`.Session.commit` or
+:meth:`.Session.rollback` is called, a pool which maintains a single
+connection must be used.   Use :class:`.SingletonThreadPool` if the scope is
+only needed within the current thread, or :class:`.StaticPool` is scope is
+needed within multiple threads for this case::
+
+    # maintain the same connection per thread
+    from sqlalchemy.pool import SingletonThreadPool
+    engine = create_engine('sqlite:///mydb.db',
+                        poolclass=SingletonThreadPool)
+
+
+    # maintain the same connection across all threads
+    from sqlalchemy.pool import StaticPool
+    engine = create_engine('sqlite:///mydb.db',
+                        poolclass=StaticPool)
+
+Note that :class:`.SingletonThreadPool` should be configured for the number
+of threads that are to be used; beyond that number, connections will be
+closed out in a non deterministic way.
+
+Unicode
+-------
+
+The pysqlite driver only returns Python ``unicode`` objects in result sets,
+never plain strings, and accommodates ``unicode`` objects within bound
+parameter values in all cases.   Regardless of the SQLAlchemy string type in
+use, string-based result values will by Python ``unicode`` in Python 2.
+The :class:`.Unicode` type should still be used to indicate those columns that
+require unicode, however, so that non-``unicode`` values passed inadvertently
+will emit a warning.  Pysqlite will emit an error if a non-``unicode`` string
+is passed containing non-ASCII characters.
+
+.. _pysqlite_serializable:
+
+Serializable Transaction Isolation
+----------------------------------
+
+The pysqlite DBAPI driver has a long-standing bug in which transactional
+state is not begun until the first DML statement, that is INSERT, UPDATE
+or DELETE, is emitted.  A SELECT statement will not cause transactional
+state to begin.   While this mode of usage is fine for typical situations
+and has the advantage that the SQLite database file is not prematurely
+locked, it breaks serializable transaction isolation, which requires
+that the database file be locked upon any SQL being emitted.
+
+To work around this issue, the ``BEGIN`` keyword can be emitted
+at the start of each transaction.   The following recipe establishes
+a :meth:`.ConnectionEvents.begin` handler to achieve this::
+
+    from sqlalchemy import create_engine, event
+
+    engine = create_engine("sqlite:///myfile.db",
+                           isolation_level='SERIALIZABLE')
+
+    @event.listens_for(engine, "begin")
+    def do_begin(conn):
+        conn.execute("BEGIN")
+
+"""
+
+from sqlalchemy.dialects.sqlite.base import SQLiteDialect, DATETIME, DATE
+from sqlalchemy import exc, pool
+from sqlalchemy import types as sqltypes
+from sqlalchemy import util
+
+import os
+
+
+class _SQLite_pysqliteTimeStamp(DATETIME):
+    def bind_processor(self, dialect):
+        if dialect.native_datetime:
+            return None
+        else:
+            return DATETIME.bind_processor(self, dialect)
+
+    def result_processor(self, dialect, coltype):
+        if dialect.native_datetime:
+            return None
+        else:
+            return DATETIME.result_processor(self, dialect, coltype)
+
+
+class _SQLite_pysqliteDate(DATE):
+    def bind_processor(self, dialect):
+        if dialect.native_datetime:
+            return None
+        else:
+            return DATE.bind_processor(self, dialect)
+
+    def result_processor(self, dialect, coltype):
+        if dialect.native_datetime:
+            return None
+        else:
+            return DATE.result_processor(self, dialect, coltype)
+
+
+class SQLiteDialect_pysqlite(SQLiteDialect):
+    default_paramstyle = 'qmark'
+
+    colspecs = util.update_copy(
+        SQLiteDialect.colspecs,
+        {
+            sqltypes.Date: _SQLite_pysqliteDate,
+            sqltypes.TIMESTAMP: _SQLite_pysqliteTimeStamp,
+        }
+    )
+
+    if not util.py2k:
+        description_encoding = None
+
+    driver = 'pysqlite'
+
+    def __init__(self, **kwargs):
+        SQLiteDialect.__init__(self, **kwargs)
+
+        if self.dbapi is not None:
+            sqlite_ver = self.dbapi.version_info
+            if sqlite_ver < (2, 1, 3):
+                util.warn(
+                    ("The installed version of pysqlite2 (%s) is out-dated "
+                     "and will cause errors in some cases.  Version 2.1.3 "
+                     "or greater is recommended.") %
+                    '.'.join([str(subver) for subver in sqlite_ver]))
+
+    @classmethod
+    def dbapi(cls):
+        try:
+            from pysqlite2 import dbapi2 as sqlite
+        except ImportError as e:
+            try:
+                from sqlite3 import dbapi2 as sqlite  # try 2.5+ stdlib name.
+            except ImportError:
+                raise e
+        return sqlite
+
+    @classmethod
+    def get_pool_class(cls, url):
+        if url.database and url.database != ':memory:':
+            return pool.NullPool
+        else:
+            return pool.SingletonThreadPool
+
+    def _get_server_version_info(self, connection):
+        return self.dbapi.sqlite_version_info
+
+    def create_connect_args(self, url):
+        if url.username or url.password or url.host or url.port:
+            raise exc.ArgumentError(
+                "Invalid SQLite URL: %s\n"
+                "Valid SQLite URL forms are:\n"
+                " sqlite:///:memory: (or, sqlite://)\n"
+                " sqlite:///relative/path/to/file.db\n"
+                " sqlite:////absolute/path/to/file.db" % (url,))
+        filename = url.database or ':memory:'
+        if filename != ':memory:':
+            filename = os.path.abspath(filename)
+
+        opts = url.query.copy()
+        util.coerce_kw_type(opts, 'timeout', float)
+        util.coerce_kw_type(opts, 'isolation_level', str)
+        util.coerce_kw_type(opts, 'detect_types', int)
+        util.coerce_kw_type(opts, 'check_same_thread', bool)
+        util.coerce_kw_type(opts, 'cached_statements', int)
+
+        return ([filename], opts)
+
+    def is_disconnect(self, e, connection, cursor):
+        return isinstance(e, self.dbapi.ProgrammingError) and \
+            "Cannot operate on a closed database." in str(e)
+
+dialect = SQLiteDialect_pysqlite