[3] | 1 | # types.py |
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| 2 | # Copyright (C) 2005, 2006, 2007, 2008, 2009 Michael Bayer mike_mp@zzzcomputing.com |
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| 3 | # |
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| 4 | # This module is part of SQLAlchemy and is released under |
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| 5 | # the MIT License: http://www.opensource.org/licenses/mit-license.php |
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| 6 | |
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| 7 | """defines genericized SQL types, each represented by a subclass of |
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| 8 | :class:`~sqlalchemy.types.AbstractType`. Dialects define further subclasses of these |
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| 9 | types. |
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| 10 | |
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| 11 | For more information see the SQLAlchemy documentation on types. |
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| 12 | |
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| 13 | """ |
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| 14 | __all__ = [ 'TypeEngine', 'TypeDecorator', 'AbstractType', |
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| 15 | 'INT', 'CHAR', 'VARCHAR', 'NCHAR', 'TEXT', 'Text', 'FLOAT', |
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| 16 | 'NUMERIC', 'DECIMAL', 'TIMESTAMP', 'DATETIME', 'CLOB', 'BLOB', |
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| 17 | 'BOOLEAN', 'SMALLINT', 'DATE', 'TIME', |
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| 18 | 'String', 'Integer', 'SmallInteger','Smallinteger', |
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| 19 | 'Numeric', 'Float', 'DateTime', 'Date', 'Time', 'Binary', |
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| 20 | 'Boolean', 'Unicode', 'MutableType', 'Concatenable', 'UnicodeText', 'PickleType', 'Interval', |
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| 21 | 'type_map' |
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| 22 | ] |
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| 23 | |
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| 24 | import inspect |
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| 25 | import datetime as dt |
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| 26 | from decimal import Decimal as _python_Decimal |
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| 27 | import weakref |
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| 28 | from sqlalchemy import exc |
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| 29 | from sqlalchemy.util import pickle |
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| 30 | import sqlalchemy.util as util |
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| 31 | NoneType = type(None) |
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| 32 | |
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| 33 | class AbstractType(object): |
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| 34 | |
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| 35 | def __init__(self, *args, **kwargs): |
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| 36 | pass |
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| 37 | |
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| 38 | def copy_value(self, value): |
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| 39 | return value |
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| 40 | |
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| 41 | def bind_processor(self, dialect): |
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| 42 | """Defines a bind parameter processing function.""" |
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| 43 | |
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| 44 | return None |
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| 45 | |
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| 46 | def result_processor(self, dialect): |
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| 47 | """Defines a result-column processing function.""" |
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| 48 | |
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| 49 | return None |
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| 50 | |
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| 51 | def compare_values(self, x, y): |
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| 52 | """Compare two values for equality.""" |
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| 53 | |
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| 54 | return x == y |
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| 55 | |
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| 56 | def is_mutable(self): |
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| 57 | """Return True if the target Python type is 'mutable'. |
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| 58 | |
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| 59 | This allows systems like the ORM to know if a column value can |
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| 60 | be considered 'not changed' by comparing the identity of |
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| 61 | objects alone. |
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| 62 | |
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| 63 | Use the :class:`MutableType` mixin or override this method to |
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| 64 | return True in custom types that hold mutable values such as |
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| 65 | ``dict``, ``list`` and custom objects. |
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| 66 | |
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| 67 | """ |
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| 68 | return False |
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| 69 | |
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| 70 | def get_dbapi_type(self, dbapi): |
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| 71 | """Return the corresponding type object from the underlying DB-API, if any. |
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| 72 | |
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| 73 | This can be useful for calling ``setinputsizes()``, for example. |
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| 74 | """ |
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| 75 | return None |
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| 76 | |
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| 77 | def adapt_operator(self, op): |
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| 78 | """Given an operator from the sqlalchemy.sql.operators package, |
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| 79 | translate it to a new operator based on the semantics of this type. |
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| 80 | |
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| 81 | By default, returns the operator unchanged. |
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| 82 | """ |
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| 83 | return op |
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| 84 | |
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| 85 | def __repr__(self): |
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| 86 | return "%s(%s)" % ( |
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| 87 | self.__class__.__name__, |
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| 88 | ", ".join("%s=%r" % (k, getattr(self, k, None)) |
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| 89 | for k in inspect.getargspec(self.__init__)[0][1:])) |
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| 90 | |
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| 91 | class TypeEngine(AbstractType): |
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| 92 | """Base for built-in types. |
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| 93 | |
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| 94 | May be sub-classed to create entirely new types. Example:: |
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| 95 | |
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| 96 | import sqlalchemy.types as types |
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| 97 | |
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| 98 | class MyType(types.TypeEngine): |
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| 99 | def __init__(self, precision = 8): |
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| 100 | self.precision = precision |
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| 101 | |
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| 102 | def get_col_spec(self): |
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| 103 | return "MYTYPE(%s)" % self.precision |
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| 104 | |
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| 105 | def bind_processor(self, dialect): |
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| 106 | def process(value): |
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| 107 | return value |
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| 108 | return process |
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| 109 | |
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| 110 | def result_processor(self, dialect): |
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| 111 | def process(value): |
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| 112 | return value |
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| 113 | return process |
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| 114 | |
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| 115 | Once the type is made, it's immediately usable:: |
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| 116 | |
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| 117 | table = Table('foo', meta, |
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| 118 | Column('id', Integer, primary_key=True), |
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| 119 | Column('data', MyType(16)) |
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| 120 | ) |
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| 121 | |
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| 122 | """ |
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| 123 | |
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| 124 | def dialect_impl(self, dialect, **kwargs): |
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| 125 | try: |
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| 126 | return self._impl_dict[dialect] |
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| 127 | except AttributeError: |
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| 128 | self._impl_dict = weakref.WeakKeyDictionary() # will be optimized in 0.6 |
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| 129 | return self._impl_dict.setdefault(dialect, dialect.type_descriptor(self)) |
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| 130 | except KeyError: |
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| 131 | return self._impl_dict.setdefault(dialect, dialect.type_descriptor(self)) |
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| 132 | |
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| 133 | def __getstate__(self): |
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| 134 | d = self.__dict__.copy() |
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| 135 | d.pop('_impl_dict', None) |
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| 136 | return d |
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| 137 | |
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| 138 | def get_col_spec(self): |
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| 139 | """Return the DDL representation for this type.""" |
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| 140 | raise NotImplementedError() |
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| 141 | |
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| 142 | def bind_processor(self, dialect): |
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| 143 | """Return a conversion function for processing bind values. |
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| 144 | |
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| 145 | Returns a callable which will receive a bind parameter value |
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| 146 | as the sole positional argument and will return a value to |
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| 147 | send to the DB-API. |
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| 148 | |
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| 149 | If processing is not necessary, the method should return ``None``. |
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| 150 | |
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| 151 | """ |
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| 152 | return None |
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| 153 | |
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| 154 | def result_processor(self, dialect): |
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| 155 | """Return a conversion function for processing result row values. |
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| 156 | |
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| 157 | Returns a callable which will receive a result row column |
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| 158 | value as the sole positional argument and will return a value |
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| 159 | to return to the user. |
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| 160 | |
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| 161 | If processing is not necessary, the method should return ``None``. |
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| 162 | |
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| 163 | """ |
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| 164 | return None |
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| 165 | |
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| 166 | def adapt(self, cls): |
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| 167 | return cls() |
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| 168 | |
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| 169 | def get_search_list(self): |
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| 170 | """return a list of classes to test for a match |
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| 171 | when adapting this type to a dialect-specific type. |
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| 172 | |
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| 173 | """ |
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| 174 | |
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| 175 | return self.__class__.__mro__[0:-1] |
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| 176 | |
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| 177 | class TypeDecorator(AbstractType): |
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| 178 | """Allows the creation of types which add additional functionality |
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| 179 | to an existing type. |
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| 180 | |
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| 181 | Typical usage:: |
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| 182 | |
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| 183 | import sqlalchemy.types as types |
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| 184 | |
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| 185 | class MyType(types.TypeDecorator): |
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| 186 | # Prefixes Unicode values with "PREFIX:" on the way in and |
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| 187 | # strips it off on the way out. |
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| 188 | |
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| 189 | impl = types.Unicode |
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| 190 | |
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| 191 | def process_bind_param(self, value, dialect): |
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| 192 | return "PREFIX:" + value |
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| 193 | |
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| 194 | def process_result_value(self, value, dialect): |
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| 195 | return value[7:] |
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| 196 | |
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| 197 | def copy(self): |
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| 198 | return MyType(self.impl.length) |
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| 199 | |
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| 200 | The class-level "impl" variable is required, and can reference any |
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| 201 | TypeEngine class. Alternatively, the load_dialect_impl() method |
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| 202 | can be used to provide different type classes based on the dialect |
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| 203 | given; in this case, the "impl" variable can reference |
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| 204 | ``TypeEngine`` as a placeholder. |
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| 205 | |
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| 206 | The reason that type behavior is modified using class decoration |
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| 207 | instead of subclassing is due to the way dialect specific types |
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| 208 | are used. Such as with the example above, when using the mysql |
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| 209 | dialect, the actual type in use will be a |
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| 210 | ``sqlalchemy.databases.mysql.MSString`` instance. |
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| 211 | ``TypeDecorator`` handles the mechanics of passing the values |
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| 212 | between user-defined ``process_`` methods and the current |
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| 213 | dialect-specific type in use. |
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| 214 | |
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| 215 | """ |
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| 216 | |
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| 217 | def __init__(self, *args, **kwargs): |
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| 218 | if not hasattr(self.__class__, 'impl'): |
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| 219 | raise AssertionError("TypeDecorator implementations require a class-level variable 'impl' which refers to the class of type being decorated") |
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| 220 | self.impl = self.__class__.impl(*args, **kwargs) |
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| 221 | |
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| 222 | def dialect_impl(self, dialect, **kwargs): |
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| 223 | try: |
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| 224 | return self._impl_dict[dialect] |
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| 225 | except AttributeError: |
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| 226 | self._impl_dict = weakref.WeakKeyDictionary() # will be optimized in 0.6 |
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| 227 | except KeyError: |
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| 228 | pass |
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| 229 | |
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| 230 | typedesc = self.load_dialect_impl(dialect) |
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| 231 | tt = self.copy() |
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| 232 | if not isinstance(tt, self.__class__): |
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| 233 | raise AssertionError("Type object %s does not properly implement the copy() " |
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| 234 | "method, it must return an object of type %s" % (self, self.__class__)) |
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| 235 | tt.impl = typedesc |
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| 236 | self._impl_dict[dialect] = tt |
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| 237 | return tt |
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| 238 | |
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| 239 | def load_dialect_impl(self, dialect): |
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| 240 | """Loads the dialect-specific implementation of this type. |
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| 241 | |
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| 242 | by default calls dialect.type_descriptor(self.impl), but |
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| 243 | can be overridden to provide different behavior. |
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| 244 | """ |
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| 245 | |
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| 246 | if isinstance(self.impl, TypeDecorator): |
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| 247 | return self.impl.dialect_impl(dialect) |
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| 248 | else: |
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| 249 | return dialect.type_descriptor(self.impl) |
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| 250 | |
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| 251 | def __getattr__(self, key): |
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| 252 | """Proxy all other undefined accessors to the underlying implementation.""" |
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| 253 | |
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| 254 | return getattr(self.impl, key) |
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| 255 | |
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| 256 | def get_col_spec(self): |
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| 257 | return self.impl.get_col_spec() |
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| 258 | |
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| 259 | def process_bind_param(self, value, dialect): |
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| 260 | raise NotImplementedError() |
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| 261 | |
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| 262 | def process_result_value(self, value, dialect): |
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| 263 | raise NotImplementedError() |
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| 264 | |
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| 265 | def bind_processor(self, dialect): |
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| 266 | if self.__class__.process_bind_param.func_code is not TypeDecorator.process_bind_param.func_code: |
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| 267 | impl_processor = self.impl.bind_processor(dialect) |
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| 268 | if impl_processor: |
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| 269 | def process(value): |
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| 270 | return impl_processor(self.process_bind_param(value, dialect)) |
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| 271 | return process |
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| 272 | else: |
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| 273 | def process(value): |
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| 274 | return self.process_bind_param(value, dialect) |
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| 275 | return process |
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| 276 | else: |
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| 277 | return self.impl.bind_processor(dialect) |
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| 278 | |
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| 279 | def result_processor(self, dialect): |
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| 280 | if self.__class__.process_result_value.func_code is not TypeDecorator.process_result_value.func_code: |
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| 281 | impl_processor = self.impl.result_processor(dialect) |
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| 282 | if impl_processor: |
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| 283 | def process(value): |
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| 284 | return self.process_result_value(impl_processor(value), dialect) |
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| 285 | return process |
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| 286 | else: |
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| 287 | def process(value): |
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| 288 | return self.process_result_value(value, dialect) |
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| 289 | return process |
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| 290 | else: |
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| 291 | return self.impl.result_processor(dialect) |
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| 292 | |
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| 293 | def copy(self): |
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| 294 | instance = self.__class__.__new__(self.__class__) |
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| 295 | instance.__dict__.update(self.__dict__) |
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| 296 | return instance |
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| 297 | |
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| 298 | def get_dbapi_type(self, dbapi): |
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| 299 | return self.impl.get_dbapi_type(dbapi) |
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| 300 | |
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| 301 | def copy_value(self, value): |
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| 302 | return self.impl.copy_value(value) |
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| 303 | |
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| 304 | def compare_values(self, x, y): |
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| 305 | return self.impl.compare_values(x, y) |
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| 306 | |
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| 307 | def is_mutable(self): |
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| 308 | return self.impl.is_mutable() |
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| 309 | |
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| 310 | class MutableType(object): |
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| 311 | """A mixin that marks a Type as holding a mutable object. |
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| 312 | |
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| 313 | :meth:`copy_value` and :meth:`compare_values` should be customized |
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| 314 | as needed to match the needs of the object. |
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| 315 | |
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| 316 | """ |
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| 317 | |
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| 318 | def is_mutable(self): |
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| 319 | """Return True, mutable.""" |
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| 320 | return True |
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| 321 | |
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| 322 | def copy_value(self, value): |
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| 323 | """Unimplemented.""" |
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| 324 | raise NotImplementedError() |
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| 325 | |
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| 326 | def compare_values(self, x, y): |
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| 327 | """Compare *x* == *y*.""" |
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| 328 | return x == y |
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| 329 | |
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| 330 | def to_instance(typeobj): |
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| 331 | if typeobj is None: |
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| 332 | return NULLTYPE |
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| 333 | |
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| 334 | try: |
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| 335 | return typeobj() |
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| 336 | except TypeError: |
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| 337 | return typeobj |
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| 338 | |
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| 339 | def adapt_type(typeobj, colspecs): |
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| 340 | if isinstance(typeobj, type): |
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| 341 | typeobj = typeobj() |
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| 342 | for t in typeobj.get_search_list(): |
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| 343 | try: |
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| 344 | impltype = colspecs[t] |
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| 345 | break |
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| 346 | except KeyError: |
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| 347 | pass |
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| 348 | else: |
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| 349 | # couldnt adapt - so just return the type itself |
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| 350 | # (it may be a user-defined type) |
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| 351 | return typeobj |
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| 352 | # if we adapted the given generic type to a database-specific type, |
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| 353 | # but it turns out the originally given "generic" type |
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| 354 | # is actually a subclass of our resulting type, then we were already |
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| 355 | # given a more specific type than that required; so use that. |
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| 356 | if (issubclass(typeobj.__class__, impltype)): |
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| 357 | return typeobj |
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| 358 | return typeobj.adapt(impltype) |
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| 359 | |
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| 360 | class NullType(TypeEngine): |
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| 361 | """An unknown type. |
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| 362 | |
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| 363 | NullTypes will stand in if :class:`~sqlalchemy.Table` reflection |
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| 364 | encounters a column data type unknown to SQLAlchemy. The |
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| 365 | resulting columns are nearly fully usable: the DB-API adapter will |
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| 366 | handle all translation to and from the database data type. |
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| 367 | |
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| 368 | NullType does not have sufficient information to particpate in a |
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| 369 | ``CREATE TABLE`` statement and will raise an exception if |
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| 370 | encountered during a :meth:`~sqlalchemy.Table.create` operation. |
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| 371 | |
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| 372 | """ |
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| 373 | |
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| 374 | def get_col_spec(self): |
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| 375 | raise NotImplementedError() |
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| 376 | |
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| 377 | NullTypeEngine = NullType |
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| 378 | |
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| 379 | class Concatenable(object): |
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| 380 | """A mixin that marks a type as supporting 'concatenation', typically strings.""" |
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| 381 | |
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| 382 | def adapt_operator(self, op): |
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| 383 | """Converts an add operator to concat.""" |
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| 384 | from sqlalchemy.sql import operators |
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| 385 | if op is operators.add: |
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| 386 | return operators.concat_op |
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| 387 | else: |
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| 388 | return op |
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| 389 | |
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| 390 | class String(Concatenable, TypeEngine): |
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| 391 | """The base for all string and character types. |
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| 392 | |
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| 393 | In SQL, corresponds to VARCHAR. Can also take Python unicode objects |
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| 394 | and encode to the database's encoding in bind params (and the reverse for |
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| 395 | result sets.) |
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| 396 | |
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| 397 | The `length` field is usually required when the `String` type is |
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| 398 | used within a CREATE TABLE statement, as VARCHAR requires a length |
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| 399 | on most databases. |
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| 400 | |
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| 401 | """ |
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| 402 | |
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| 403 | def __init__(self, length=None, convert_unicode=False, assert_unicode=None): |
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| 404 | """ |
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| 405 | Create a string-holding type. |
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| 406 | |
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| 407 | :param length: optional, a length for the column for use in |
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| 408 | DDL statements. May be safely omitted if no ``CREATE |
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| 409 | TABLE`` will be issued. Certain databases may require a |
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| 410 | *length* for use in DDL, and will raise an exception when |
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| 411 | the ``CREATE TABLE`` DDL is issued. Whether the value is |
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| 412 | interpreted as bytes or characters is database specific. |
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| 413 | |
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| 414 | :param convert_unicode: defaults to False. If True, convert |
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| 415 | ``unicode`` data sent to the database to a ``str`` |
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| 416 | bytestring, and convert bytestrings coming back from the |
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| 417 | database into ``unicode``. |
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| 418 | |
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| 419 | Bytestrings are encoded using the dialect's |
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| 420 | :attr:`~sqlalchemy.engine.base.Dialect.encoding`, which |
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| 421 | defaults to `utf-8`. |
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| 422 | |
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| 423 | If False, may be overridden by |
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| 424 | :attr:`sqlalchemy.engine.base.Dialect.convert_unicode`. |
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| 425 | |
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| 426 | :param assert_unicode: |
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| 427 | |
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| 428 | If None (the default), no assertion will take place unless |
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| 429 | overridden by :attr:`sqlalchemy.engine.base.Dialect.assert_unicode`. |
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| 430 | |
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| 431 | If 'warn', will issue a runtime warning if a ``str`` |
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| 432 | instance is used as a bind value. |
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| 433 | |
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| 434 | If true, will raise an :exc:`sqlalchemy.exc.InvalidRequestError`. |
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| 435 | |
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| 436 | """ |
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| 437 | self.length = length |
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| 438 | self.convert_unicode = convert_unicode |
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| 439 | self.assert_unicode = assert_unicode |
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| 440 | |
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| 441 | def adapt(self, impltype): |
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| 442 | return impltype(length=self.length, convert_unicode=self.convert_unicode, assert_unicode=self.assert_unicode) |
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| 443 | |
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| 444 | def bind_processor(self, dialect): |
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| 445 | if self.convert_unicode or dialect.convert_unicode: |
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| 446 | if self.assert_unicode is None: |
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| 447 | assert_unicode = dialect.assert_unicode |
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| 448 | else: |
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| 449 | assert_unicode = self.assert_unicode |
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| 450 | def process(value): |
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| 451 | if isinstance(value, unicode): |
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| 452 | return value.encode(dialect.encoding) |
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| 453 | elif assert_unicode and not isinstance(value, (unicode, NoneType)): |
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| 454 | if assert_unicode == 'warn': |
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| 455 | util.warn("Unicode type received non-unicode bind " |
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| 456 | "param value %r" % value) |
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| 457 | return value |
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| 458 | else: |
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| 459 | raise exc.InvalidRequestError("Unicode type received non-unicode bind param value %r" % value) |
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| 460 | else: |
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| 461 | return value |
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| 462 | return process |
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| 463 | else: |
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| 464 | return None |
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| 465 | |
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| 466 | def result_processor(self, dialect): |
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| 467 | if self.convert_unicode or dialect.convert_unicode: |
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| 468 | def process(value): |
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| 469 | if value is not None and not isinstance(value, unicode): |
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| 470 | return value.decode(dialect.encoding) |
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| 471 | else: |
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| 472 | return value |
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| 473 | return process |
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| 474 | else: |
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| 475 | return None |
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| 476 | |
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| 477 | def get_dbapi_type(self, dbapi): |
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| 478 | return dbapi.STRING |
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| 479 | |
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| 480 | class Text(String): |
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| 481 | """A variably sized string type. |
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| 482 | |
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| 483 | In SQL, usually corresponds to CLOB or TEXT. Can also take Python |
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| 484 | unicode objects and encode to the database's encoding in bind |
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| 485 | params (and the reverse for result sets.) |
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| 486 | |
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| 487 | """ |
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| 488 | |
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| 489 | class Unicode(String): |
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| 490 | """A variable length Unicode string. |
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| 491 | |
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| 492 | The ``Unicode`` type is a :class:`String` which converts Python |
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| 493 | ``unicode`` objects (i.e., strings that are defined as |
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| 494 | ``u'somevalue'``) into encoded bytestrings when passing the value |
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| 495 | to the database driver, and similarly decodes values from the |
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| 496 | database back into Python ``unicode`` objects. |
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| 497 | |
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| 498 | When using the ``Unicode`` type, it is only appropriate to pass |
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| 499 | Python ``unicode`` objects, and not plain ``str``. If a |
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| 500 | bytestring (``str``) is passed, a runtime warning is issued. If |
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| 501 | you notice your application raising these warnings but you're not |
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| 502 | sure where, the Python ``warnings`` filter can be used to turn |
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| 503 | these warnings into exceptions which will illustrate a stack |
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| 504 | trace:: |
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| 505 | |
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| 506 | import warnings |
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| 507 | warnings.simplefilter('error') |
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| 508 | |
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| 509 | Bytestrings sent to and received from the database are encoded |
---|
| 510 | using the dialect's |
---|
| 511 | :attr:`~sqlalchemy.engine.base.Dialect.encoding`, which defaults |
---|
| 512 | to `utf-8`. |
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| 513 | |
---|
| 514 | A synonym for String(length, convert_unicode=True, assert_unicode='warn'). |
---|
| 515 | |
---|
| 516 | """ |
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| 517 | |
---|
| 518 | def __init__(self, length=None, **kwargs): |
---|
| 519 | """ |
---|
| 520 | Create a Unicode-converting String type. |
---|
| 521 | |
---|
| 522 | :param length: optional, a length for the column for use in |
---|
| 523 | DDL statements. May be safely omitted if no ``CREATE |
---|
| 524 | TABLE`` will be issued. Certain databases may require a |
---|
| 525 | *length* for use in DDL, and will raise an exception when |
---|
| 526 | the ``CREATE TABLE`` DDL is issued. Whether the value is |
---|
| 527 | interpreted as bytes or characters is database specific. |
---|
| 528 | |
---|
| 529 | """ |
---|
| 530 | kwargs.setdefault('convert_unicode', True) |
---|
| 531 | kwargs.setdefault('assert_unicode', 'warn') |
---|
| 532 | super(Unicode, self).__init__(length=length, **kwargs) |
---|
| 533 | |
---|
| 534 | class UnicodeText(Text): |
---|
| 535 | """A synonym for Text(convert_unicode=True, assert_unicode='warn').""" |
---|
| 536 | |
---|
| 537 | def __init__(self, length=None, **kwargs): |
---|
| 538 | """ |
---|
| 539 | Create a Unicode-converting Text type. |
---|
| 540 | |
---|
| 541 | :param length: optional, a length for the column for use in |
---|
| 542 | DDL statements. May be safely omitted if no ``CREATE |
---|
| 543 | TABLE`` will be issued. Certain databases may require a |
---|
| 544 | *length* for use in DDL, and will raise an exception when |
---|
| 545 | the ``CREATE TABLE`` DDL is issued. Whether the value is |
---|
| 546 | interpreted as bytes or characters is database specific. |
---|
| 547 | |
---|
| 548 | """ |
---|
| 549 | kwargs.setdefault('convert_unicode', True) |
---|
| 550 | kwargs.setdefault('assert_unicode', 'warn') |
---|
| 551 | super(UnicodeText, self).__init__(length=length, **kwargs) |
---|
| 552 | |
---|
| 553 | |
---|
| 554 | class Integer(TypeEngine): |
---|
| 555 | """A type for ``int`` integers.""" |
---|
| 556 | |
---|
| 557 | def get_dbapi_type(self, dbapi): |
---|
| 558 | return dbapi.NUMBER |
---|
| 559 | |
---|
| 560 | |
---|
| 561 | class SmallInteger(Integer): |
---|
| 562 | """A type for smaller ``int`` integers. |
---|
| 563 | |
---|
| 564 | Typically generates a ``SMALLINT`` in DDL, and otherwise acts like |
---|
| 565 | a normal :class:`Integer` on the Python side. |
---|
| 566 | |
---|
| 567 | """ |
---|
| 568 | |
---|
| 569 | Smallinteger = SmallInteger |
---|
| 570 | |
---|
| 571 | class Numeric(TypeEngine): |
---|
| 572 | """A type for fixed precision numbers. |
---|
| 573 | |
---|
| 574 | Typically generates DECIMAL or NUMERIC. Returns |
---|
| 575 | ``decimal.Decimal`` objects by default. |
---|
| 576 | |
---|
| 577 | """ |
---|
| 578 | |
---|
| 579 | def __init__(self, precision=10, scale=2, asdecimal=True, length=None): |
---|
| 580 | """ |
---|
| 581 | Construct a Numeric. |
---|
| 582 | |
---|
| 583 | :param precision: the numeric precision for use in DDL ``CREATE TABLE``. |
---|
| 584 | |
---|
| 585 | :param scale: the numeric scale for use in DDL ``CREATE TABLE``. |
---|
| 586 | |
---|
| 587 | :param asdecimal: default True. If False, values will be |
---|
| 588 | returned as-is from the DB-API, and may be either |
---|
| 589 | ``Decimal`` or ``float`` types depending on the DB-API in |
---|
| 590 | use. |
---|
| 591 | |
---|
| 592 | """ |
---|
| 593 | if length: |
---|
| 594 | util.warn_deprecated("'length' is deprecated for Numeric. Use 'scale'.") |
---|
| 595 | scale = length |
---|
| 596 | self.precision = precision |
---|
| 597 | self.scale = scale |
---|
| 598 | self.asdecimal = asdecimal |
---|
| 599 | |
---|
| 600 | def adapt(self, impltype): |
---|
| 601 | return impltype(precision=self.precision, scale=self.scale, asdecimal=self.asdecimal) |
---|
| 602 | |
---|
| 603 | def get_dbapi_type(self, dbapi): |
---|
| 604 | return dbapi.NUMBER |
---|
| 605 | |
---|
| 606 | def bind_processor(self, dialect): |
---|
| 607 | def process(value): |
---|
| 608 | if value is not None: |
---|
| 609 | return float(value) |
---|
| 610 | else: |
---|
| 611 | return value |
---|
| 612 | return process |
---|
| 613 | |
---|
| 614 | def result_processor(self, dialect): |
---|
| 615 | if self.asdecimal: |
---|
| 616 | def process(value): |
---|
| 617 | if value is not None: |
---|
| 618 | return _python_Decimal(str(value)) |
---|
| 619 | else: |
---|
| 620 | return value |
---|
| 621 | return process |
---|
| 622 | else: |
---|
| 623 | return None |
---|
| 624 | |
---|
| 625 | |
---|
| 626 | class Float(Numeric): |
---|
| 627 | """A type for ``float`` numbers.""" |
---|
| 628 | |
---|
| 629 | def __init__(self, precision=10, asdecimal=False, **kwargs): |
---|
| 630 | """ |
---|
| 631 | Construct a Float. |
---|
| 632 | |
---|
| 633 | :param precision: the numeric precision for use in DDL ``CREATE TABLE``. |
---|
| 634 | |
---|
| 635 | """ |
---|
| 636 | self.precision = precision |
---|
| 637 | self.asdecimal = asdecimal |
---|
| 638 | |
---|
| 639 | def adapt(self, impltype): |
---|
| 640 | return impltype(precision=self.precision, asdecimal=self.asdecimal) |
---|
| 641 | |
---|
| 642 | |
---|
| 643 | class DateTime(TypeEngine): |
---|
| 644 | """A type for ``datetime.datetime()`` objects. |
---|
| 645 | |
---|
| 646 | Date and time types return objects from the Python ``datetime`` |
---|
| 647 | module. Most DBAPIs have built in support for the datetime |
---|
| 648 | module, with the noted exception of SQLite. In the case of |
---|
| 649 | SQLite, date and time types are stored as strings which are then |
---|
| 650 | converted back to datetime objects when rows are returned. |
---|
| 651 | |
---|
| 652 | """ |
---|
| 653 | |
---|
| 654 | def __init__(self, timezone=False): |
---|
| 655 | self.timezone = timezone |
---|
| 656 | |
---|
| 657 | def adapt(self, impltype): |
---|
| 658 | return impltype(timezone=self.timezone) |
---|
| 659 | |
---|
| 660 | def get_dbapi_type(self, dbapi): |
---|
| 661 | return dbapi.DATETIME |
---|
| 662 | |
---|
| 663 | |
---|
| 664 | class Date(TypeEngine): |
---|
| 665 | """A type for ``datetime.date()`` objects.""" |
---|
| 666 | |
---|
| 667 | def get_dbapi_type(self, dbapi): |
---|
| 668 | return dbapi.DATETIME |
---|
| 669 | |
---|
| 670 | |
---|
| 671 | class Time(TypeEngine): |
---|
| 672 | """A type for ``datetime.time()`` objects.""" |
---|
| 673 | |
---|
| 674 | def __init__(self, timezone=False): |
---|
| 675 | self.timezone = timezone |
---|
| 676 | |
---|
| 677 | def adapt(self, impltype): |
---|
| 678 | return impltype(timezone=self.timezone) |
---|
| 679 | |
---|
| 680 | def get_dbapi_type(self, dbapi): |
---|
| 681 | return dbapi.DATETIME |
---|
| 682 | |
---|
| 683 | |
---|
| 684 | class Binary(TypeEngine): |
---|
| 685 | """A type for binary byte data. |
---|
| 686 | |
---|
| 687 | The Binary type generates BLOB or BYTEA when tables are created, |
---|
| 688 | and also converts incoming values using the ``Binary`` callable |
---|
| 689 | provided by each DB-API. |
---|
| 690 | |
---|
| 691 | """ |
---|
| 692 | |
---|
| 693 | def __init__(self, length=None): |
---|
| 694 | """ |
---|
| 695 | Construct a Binary type. |
---|
| 696 | |
---|
| 697 | :param length: optional, a length for the column for use in |
---|
| 698 | DDL statements. May be safely omitted if no ``CREATE |
---|
| 699 | TABLE`` will be issued. Certain databases may require a |
---|
| 700 | *length* for use in DDL, and will raise an exception when |
---|
| 701 | the ``CREATE TABLE`` DDL is issued. |
---|
| 702 | |
---|
| 703 | """ |
---|
| 704 | self.length = length |
---|
| 705 | |
---|
| 706 | def bind_processor(self, dialect): |
---|
| 707 | DBAPIBinary = dialect.dbapi.Binary |
---|
| 708 | def process(value): |
---|
| 709 | if value is not None: |
---|
| 710 | return DBAPIBinary(value) |
---|
| 711 | else: |
---|
| 712 | return None |
---|
| 713 | return process |
---|
| 714 | |
---|
| 715 | def adapt(self, impltype): |
---|
| 716 | return impltype(length=self.length) |
---|
| 717 | |
---|
| 718 | def get_dbapi_type(self, dbapi): |
---|
| 719 | return dbapi.BINARY |
---|
| 720 | |
---|
| 721 | |
---|
| 722 | class PickleType(MutableType, TypeDecorator): |
---|
| 723 | """Holds Python objects. |
---|
| 724 | |
---|
| 725 | PickleType builds upon the Binary type to apply Python's |
---|
| 726 | ``pickle.dumps()`` to incoming objects, and ``pickle.loads()`` on |
---|
| 727 | the way out, allowing any pickleable Python object to be stored as |
---|
| 728 | a serialized binary field. |
---|
| 729 | |
---|
| 730 | """ |
---|
| 731 | |
---|
| 732 | impl = Binary |
---|
| 733 | |
---|
| 734 | def __init__(self, protocol=pickle.HIGHEST_PROTOCOL, pickler=None, mutable=True, comparator=None): |
---|
| 735 | """ |
---|
| 736 | Construct a PickleType. |
---|
| 737 | |
---|
| 738 | :param protocol: defaults to ``pickle.HIGHEST_PROTOCOL``. |
---|
| 739 | |
---|
| 740 | :param pickler: defaults to cPickle.pickle or pickle.pickle if |
---|
| 741 | cPickle is not available. May be any object with |
---|
| 742 | pickle-compatible ``dumps` and ``loads`` methods. |
---|
| 743 | |
---|
| 744 | :param mutable: defaults to True; implements |
---|
| 745 | :meth:`AbstractType.is_mutable`. When ``True``, incoming |
---|
| 746 | objects *must* provide an ``__eq__()`` method which |
---|
| 747 | performs the desired deep comparison of members, or the |
---|
| 748 | ``comparator`` argument must be present. Otherwise, |
---|
| 749 | comparisons are done by comparing pickle strings. |
---|
| 750 | The pickle form of comparison is a deprecated usage and will |
---|
| 751 | raise a warning. |
---|
| 752 | |
---|
| 753 | :param comparator: optional. a 2-arg callable predicate used |
---|
| 754 | to compare values of this type. Otherwise, either |
---|
| 755 | the == operator is used to compare values, or if mutable==True |
---|
| 756 | and the incoming object does not implement __eq__(), the value |
---|
| 757 | of pickle.dumps(obj) is compared. The last option is a deprecated |
---|
| 758 | usage and will raise a warning. |
---|
| 759 | |
---|
| 760 | """ |
---|
| 761 | self.protocol = protocol |
---|
| 762 | self.pickler = pickler or pickle |
---|
| 763 | self.mutable = mutable |
---|
| 764 | self.comparator = comparator |
---|
| 765 | super(PickleType, self).__init__() |
---|
| 766 | |
---|
| 767 | def process_bind_param(self, value, dialect): |
---|
| 768 | dumps = self.pickler.dumps |
---|
| 769 | protocol = self.protocol |
---|
| 770 | if value is None: |
---|
| 771 | return None |
---|
| 772 | return dumps(value, protocol) |
---|
| 773 | |
---|
| 774 | def process_result_value(self, value, dialect): |
---|
| 775 | loads = self.pickler.loads |
---|
| 776 | if value is None: |
---|
| 777 | return None |
---|
| 778 | return loads(str(value)) |
---|
| 779 | |
---|
| 780 | def copy_value(self, value): |
---|
| 781 | if self.mutable: |
---|
| 782 | return self.pickler.loads(self.pickler.dumps(value, self.protocol)) |
---|
| 783 | else: |
---|
| 784 | return value |
---|
| 785 | |
---|
| 786 | def compare_values(self, x, y): |
---|
| 787 | if self.comparator: |
---|
| 788 | return self.comparator(x, y) |
---|
| 789 | elif self.mutable and not hasattr(x, '__eq__') and x is not None: |
---|
| 790 | util.warn_deprecated("Objects stored with PickleType when mutable=True must implement __eq__() for reliable comparison.") |
---|
| 791 | return self.pickler.dumps(x, self.protocol) == self.pickler.dumps(y, self.protocol) |
---|
| 792 | else: |
---|
| 793 | return x == y |
---|
| 794 | |
---|
| 795 | def is_mutable(self): |
---|
| 796 | return self.mutable |
---|
| 797 | |
---|
| 798 | |
---|
| 799 | class Boolean(TypeEngine): |
---|
| 800 | """A bool datatype. |
---|
| 801 | |
---|
| 802 | Boolean typically uses BOOLEAN or SMALLINT on the DDL side, and on |
---|
| 803 | the Python side deals in ``True`` or ``False``. |
---|
| 804 | |
---|
| 805 | """ |
---|
| 806 | |
---|
| 807 | |
---|
| 808 | class Interval(TypeDecorator): |
---|
| 809 | """A type for ``datetime.timedelta()`` objects. |
---|
| 810 | |
---|
| 811 | The Interval type deals with ``datetime.timedelta`` objects. In |
---|
| 812 | PostgreSQL, the native ``INTERVAL`` type is used; for others, the |
---|
| 813 | value is stored as a date which is relative to the "epoch" |
---|
| 814 | (Jan. 1, 1970). |
---|
| 815 | |
---|
| 816 | """ |
---|
| 817 | |
---|
| 818 | impl = TypeEngine |
---|
| 819 | |
---|
| 820 | def __init__(self): |
---|
| 821 | super(Interval, self).__init__() |
---|
| 822 | import sqlalchemy.databases.postgres as pg |
---|
| 823 | self.__supported = {pg.PGDialect:pg.PGInterval} |
---|
| 824 | del pg |
---|
| 825 | |
---|
| 826 | def load_dialect_impl(self, dialect): |
---|
| 827 | if dialect.__class__ in self.__supported: |
---|
| 828 | return self.__supported[dialect.__class__]() |
---|
| 829 | else: |
---|
| 830 | return dialect.type_descriptor(DateTime) |
---|
| 831 | |
---|
| 832 | def process_bind_param(self, value, dialect): |
---|
| 833 | if dialect.__class__ in self.__supported: |
---|
| 834 | return value |
---|
| 835 | else: |
---|
| 836 | if value is None: |
---|
| 837 | return None |
---|
| 838 | return dt.datetime.utcfromtimestamp(0) + value |
---|
| 839 | |
---|
| 840 | def process_result_value(self, value, dialect): |
---|
| 841 | if dialect.__class__ in self.__supported: |
---|
| 842 | return value |
---|
| 843 | else: |
---|
| 844 | if value is None: |
---|
| 845 | return None |
---|
| 846 | return value - dt.datetime.utcfromtimestamp(0) |
---|
| 847 | |
---|
| 848 | class FLOAT(Float): |
---|
| 849 | """The SQL FLOAT type.""" |
---|
| 850 | |
---|
| 851 | |
---|
| 852 | class NUMERIC(Numeric): |
---|
| 853 | """The SQL NUMERIC type.""" |
---|
| 854 | |
---|
| 855 | |
---|
| 856 | class DECIMAL(Numeric): |
---|
| 857 | """The SQL DECIMAL type.""" |
---|
| 858 | |
---|
| 859 | |
---|
| 860 | class INT(Integer): |
---|
| 861 | """The SQL INT or INTEGER type.""" |
---|
| 862 | |
---|
| 863 | |
---|
| 864 | INTEGER = INT |
---|
| 865 | |
---|
| 866 | class SMALLINT(Smallinteger): |
---|
| 867 | """The SQL SMALLINT type.""" |
---|
| 868 | |
---|
| 869 | |
---|
| 870 | class TIMESTAMP(DateTime): |
---|
| 871 | """The SQL TIMESTAMP type.""" |
---|
| 872 | |
---|
| 873 | |
---|
| 874 | class DATETIME(DateTime): |
---|
| 875 | """The SQL DATETIME type.""" |
---|
| 876 | |
---|
| 877 | |
---|
| 878 | class DATE(Date): |
---|
| 879 | """The SQL DATE type.""" |
---|
| 880 | |
---|
| 881 | |
---|
| 882 | class TIME(Time): |
---|
| 883 | """The SQL TIME type.""" |
---|
| 884 | |
---|
| 885 | |
---|
| 886 | TEXT = Text |
---|
| 887 | |
---|
| 888 | class CLOB(Text): |
---|
| 889 | """The SQL CLOB type.""" |
---|
| 890 | |
---|
| 891 | |
---|
| 892 | class VARCHAR(String): |
---|
| 893 | """The SQL VARCHAR type.""" |
---|
| 894 | |
---|
| 895 | |
---|
| 896 | class CHAR(String): |
---|
| 897 | """The SQL CHAR type.""" |
---|
| 898 | |
---|
| 899 | |
---|
| 900 | class NCHAR(Unicode): |
---|
| 901 | """The SQL NCHAR type.""" |
---|
| 902 | |
---|
| 903 | |
---|
| 904 | class BLOB(Binary): |
---|
| 905 | """The SQL BLOB type.""" |
---|
| 906 | |
---|
| 907 | |
---|
| 908 | class BOOLEAN(Boolean): |
---|
| 909 | """The SQL BOOLEAN type.""" |
---|
| 910 | |
---|
| 911 | NULLTYPE = NullType() |
---|
| 912 | |
---|
| 913 | # using VARCHAR/NCHAR so that we dont get the genericized "String" |
---|
| 914 | # type which usually resolves to TEXT/CLOB |
---|
| 915 | type_map = { |
---|
| 916 | str : VARCHAR, |
---|
| 917 | unicode : NCHAR, |
---|
| 918 | int : Integer, |
---|
| 919 | float : Numeric, |
---|
| 920 | bool: Boolean, |
---|
| 921 | _python_Decimal : Numeric, |
---|
| 922 | dt.date : Date, |
---|
| 923 | dt.datetime : DateTime, |
---|
| 924 | dt.time : Time, |
---|
| 925 | dt.timedelta : Interval, |
---|
| 926 | type(None): NullType |
---|
| 927 | } |
---|