127 lines
3.8 KiB
Python
127 lines
3.8 KiB
Python
# postgresql/pg8000.py
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# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""
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.. dialect:: postgresql+pg8000
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:name: pg8000
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:dbapi: pg8000
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:connectstring: postgresql+pg8000://user:password@host:port/dbname[?key=value&key=value...]
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:url: http://pybrary.net/pg8000/
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Unicode
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-------
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pg8000 requires that the postgresql client encoding be
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configured in the postgresql.conf file in order to use encodings
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other than ascii. Set this value to the same value as the
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"encoding" parameter on create_engine(), usually "utf-8".
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Interval
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--------
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Passing data from/to the Interval type is not supported as of
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yet.
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"""
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from ... import util, exc
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import decimal
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from ... import processors
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from ... import types as sqltypes
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from .base import PGDialect, \
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PGCompiler, PGIdentifierPreparer, PGExecutionContext,\
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_DECIMAL_TYPES, _FLOAT_TYPES, _INT_TYPES
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class _PGNumeric(sqltypes.Numeric):
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def result_processor(self, dialect, coltype):
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if self.asdecimal:
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if coltype in _FLOAT_TYPES:
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return processors.to_decimal_processor_factory(
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decimal.Decimal,
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self._effective_decimal_return_scale)
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elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES:
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# pg8000 returns Decimal natively for 1700
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return None
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else:
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raise exc.InvalidRequestError(
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"Unknown PG numeric type: %d" % coltype)
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else:
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if coltype in _FLOAT_TYPES:
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# pg8000 returns float natively for 701
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return None
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elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES:
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return processors.to_float
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else:
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raise exc.InvalidRequestError(
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"Unknown PG numeric type: %d" % coltype)
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class _PGNumericNoBind(_PGNumeric):
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def bind_processor(self, dialect):
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return None
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class PGExecutionContext_pg8000(PGExecutionContext):
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pass
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class PGCompiler_pg8000(PGCompiler):
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def visit_mod_binary(self, binary, operator, **kw):
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return self.process(binary.left, **kw) + " %% " + \
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self.process(binary.right, **kw)
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def post_process_text(self, text):
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if '%%' in text:
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util.warn("The SQLAlchemy postgresql dialect "
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"now automatically escapes '%' in text() "
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"expressions to '%%'.")
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return text.replace('%', '%%')
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class PGIdentifierPreparer_pg8000(PGIdentifierPreparer):
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def _escape_identifier(self, value):
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value = value.replace(self.escape_quote, self.escape_to_quote)
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return value.replace('%', '%%')
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class PGDialect_pg8000(PGDialect):
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driver = 'pg8000'
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supports_unicode_statements = True
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supports_unicode_binds = True
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default_paramstyle = 'format'
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supports_sane_multi_rowcount = False
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execution_ctx_cls = PGExecutionContext_pg8000
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statement_compiler = PGCompiler_pg8000
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preparer = PGIdentifierPreparer_pg8000
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description_encoding = 'use_encoding'
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colspecs = util.update_copy(
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PGDialect.colspecs,
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{
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sqltypes.Numeric: _PGNumericNoBind,
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sqltypes.Float: _PGNumeric
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}
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)
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@classmethod
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def dbapi(cls):
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return __import__('pg8000').dbapi
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def create_connect_args(self, url):
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opts = url.translate_connect_args(username='user')
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if 'port' in opts:
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opts['port'] = int(opts['port'])
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opts.update(url.query)
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return ([], opts)
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def is_disconnect(self, e, connection, cursor):
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return "connection is closed" in str(e)
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dialect = PGDialect_pg8000
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