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Diffstat (limited to 'lib/sqlalchemy/dialects/mssql/pymssql.py')
| -rw-r--r-- | lib/sqlalchemy/dialects/mssql/pymssql.py | 85 |
1 files changed, 73 insertions, 12 deletions
diff --git a/lib/sqlalchemy/dialects/mssql/pymssql.py b/lib/sqlalchemy/dialects/mssql/pymssql.py index b3a57d318..ca1c4a142 100644 --- a/lib/sqlalchemy/dialects/mssql/pymssql.py +++ b/lib/sqlalchemy/dialects/mssql/pymssql.py @@ -1,40 +1,101 @@ """ Support for the pymssql dialect. -Going forward we will be supporting the 1.0 release of pymssql. +This dialect supports pymssql 1.0 and greater. + +pymssql is available at: + + http://pymssql.sourceforge.net/ + +Connecting +^^^^^^^^^^ + +Sample connect string:: + + mssql+pymssql://<username>:<password>@<freetds_name> + +Adding "?charset=utf8" or similar will cause pymssql to return +strings as Python unicode objects. This can potentially improve +performance in some scenarios as decoding of strings is +handled natively. + +Limitations +^^^^^^^^^^^ + +pymssql inherits a lot of limitations from FreeTDS, including: + +* no support for multibyte schema identifiers +* poor support for large decimals +* poor support for binary fields +* poor support for VARCHAR/CHAR fields over 255 characters + +Please consult the pymssql documentation for further information. """ from sqlalchemy.dialects.mssql.base import MSDialect -from sqlalchemy import types as sqltypes +from sqlalchemy import types as sqltypes, util, processors +import re +import decimal +class _MSNumeric_pymssql(sqltypes.Numeric): + def result_processor(self, dialect, type_): + if not self.asdecimal: + return processors.to_float + else: + return sqltypes.Numeric.result_processor(self, dialect, type_) class MSDialect_pymssql(MSDialect): supports_sane_rowcount = False max_identifier_length = 30 driver = 'pymssql' - + + colspecs = util.update_copy( + MSDialect.colspecs, + { + sqltypes.Numeric:_MSNumeric_pymssql, + sqltypes.Float:sqltypes.Float, + } + ) @classmethod def dbapi(cls): - import pymssql as module + module = __import__('pymssql') # pymmsql doesn't have a Binary method. we use string # TODO: monkeypatching here is less than ideal - module.Binary = lambda st: str(st) + module.Binary = str + + client_ver = tuple(int(x) for x in module.__version__.split(".")) + if client_ver < (1, ): + util.warn("The pymssql dialect expects at least " + "the 1.0 series of the pymssql DBAPI.") return module def __init__(self, **params): super(MSDialect_pymssql, self).__init__(**params) self.use_scope_identity = True + def _get_server_version_info(self, connection): + vers = connection.scalar("select @@version") + m = re.match(r"Microsoft SQL Server.*? - (\d+).(\d+).(\d+).(\d+)", vers) + if m: + return tuple(int(x) for x in m.group(1, 2, 3, 4)) + else: + return None def create_connect_args(self, url): - keys = url.query - if keys.get('port'): - # pymssql expects port as host:port, not a separate arg - keys['host'] = ''.join([keys.get('host', ''), ':', str(keys['port'])]) - del keys['port'] - return [[], keys] + opts = url.translate_connect_args(username='user') + opts.update(url.query) + opts.pop('port', None) + return [[], opts] def is_disconnect(self, e): - return isinstance(e, self.dbapi.DatabaseError) and "Error 10054" in str(e) + for msg in ( + "Error 10054", + "Not connected to any MS SQL server", + "Connection is closed" + ): + if msg in str(e): + return True + else: + return False dialect = MSDialect_pymssql
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