"""Support for the PostgreSQL database via py-postgresql.
Connecting
----------
URLs are of the form `postgresql+pypostgresql://user@password@host:port/dbname[?key=value&key=value...]`.
"""
from sqlalchemy.engine import default
import decimal
from sqlalchemy import util
from sqlalchemy import types
from sqlalchemy.dialects.postgresql.base import PGDialect,PGExecutionContext
from sqlalchemy import processors
class PGNumeric(sqltypes.Numeric):
def bind_processor(self, dialect):
return processors.to_str
def result_processor(self, dialect, coltype):
if self.asdecimal:
return None
else:
return processors.to_float
class PGExecutionContext_pypostgresql(PGExecutionContext):
pass
class PGDialect_pypostgresql(PGDialect):
driver = 'pypostgresql'
supports_unicode_statements = True
supports_unicode_binds = True
description_encoding = None
default_paramstyle = 'pyformat'
# requires trunk version to support sane rowcounts
# TODO: use dbapi version information to set this flag appropariately
supports_sane_rowcount = True
supports_sane_multi_rowcount = False
execution_ctx_cls = PGExecutionContext_pypostgresql
colspecs = util.update_copy(
PGDialect.colspecs,
{
sqltypes.Numeric : PGNumeric,
sqltypes.Float: sqltypes.Float, # prevents PGNumeric from being used
}
)
@classmethod
def dbapi(cls):
from postgresql.driver import dbapi20
return dbapi20
def create_connect_args(self, url):
opts = url.translate_connect_args(username='user')
if 'port' in opts:
opts['port'] = int(opts['port'])
else:
opts['port'] = 5432
opts.update(url.query)
return ([], opts)
def is_disconnect(self, e):
return "connection is closed" in str(e)
dialect = PGDialect_pypostgresql
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