diff options
Diffstat (limited to 'lib/sqlalchemy/sql/schema.py')
| -rw-r--r-- | lib/sqlalchemy/sql/schema.py | 116 |
1 files changed, 70 insertions, 46 deletions
diff --git a/lib/sqlalchemy/sql/schema.py b/lib/sqlalchemy/sql/schema.py index 96cabbf4f..b90f7fc53 100644 --- a/lib/sqlalchemy/sql/schema.py +++ b/lib/sqlalchemy/sql/schema.py @@ -824,7 +824,7 @@ class Table(DialectKWArgs, SchemaItem, TableClause): table.append_constraint( c.copy(schema=fk_constraint_schema, target_table=table)) - else: + elif not c._type_bound: table.append_constraint( c.copy(schema=schema, target_table=table)) for index in self.indexes: @@ -1295,7 +1295,7 @@ class Column(SchemaItem, ColumnClause): # Constraint objects plus non-constraint-bound ForeignKey objects args = \ - [c.copy(**kw) for c in self.constraints] + \ + [c.copy(**kw) for c in self.constraints if not c._type_bound] + \ [c.copy(**kw) for c in self.foreign_keys if not c.constraint] type_ = self.type @@ -1804,7 +1804,7 @@ class ForeignKey(DialectKWArgs, SchemaItem): match=self.match, **self._unvalidated_dialect_kw ) - self.constraint._elements[self.parent] = self + self.constraint._append_element(column, self) self.constraint._set_parent_with_dispatch(table) table.foreign_keys.add(self) @@ -2254,7 +2254,7 @@ class Constraint(DialectKWArgs, SchemaItem): __visit_name__ = 'constraint' def __init__(self, name=None, deferrable=None, initially=None, - _create_rule=None, info=None, + _create_rule=None, info=None, _type_bound=False, **dialect_kw): """Create a SQL constraint. @@ -2304,6 +2304,7 @@ class Constraint(DialectKWArgs, SchemaItem): if info: self.info = info self._create_rule = _create_rule + self._type_bound = _type_bound util.set_creation_order(self) self._validate_dialect_kwargs(dialect_kw) @@ -2420,7 +2421,7 @@ class CheckConstraint(Constraint): def __init__(self, sqltext, name=None, deferrable=None, initially=None, table=None, info=None, _create_rule=None, - _autoattach=True): + _autoattach=True, _type_bound=False): """Construct a CHECK constraint. :param sqltext: @@ -2450,7 +2451,9 @@ class CheckConstraint(Constraint): """ super(CheckConstraint, self).\ - __init__(name, deferrable, initially, _create_rule, info=info) + __init__( + name, deferrable, initially, _create_rule, info=info, + _type_bound=_type_bound) self.sqltext = _literal_as_text(sqltext, warn=False) if table is not None: self._set_parent_with_dispatch(table) @@ -2485,11 +2488,12 @@ class CheckConstraint(Constraint): deferrable=self.deferrable, _create_rule=self._create_rule, table=target_table, - _autoattach=False) + _autoattach=False, + _type_bound=self._type_bound) return self._schema_item_copy(c) -class ForeignKeyConstraint(Constraint): +class ForeignKeyConstraint(ColumnCollectionConstraint): """A table-level FOREIGN KEY constraint. Defines a single column or composite FOREIGN KEY ... REFERENCES @@ -2564,9 +2568,10 @@ class ForeignKeyConstraint(Constraint): .. versionadded:: 0.9.2 """ - super(ForeignKeyConstraint, self).\ - __init__(name, deferrable, initially, info=info, **dialect_kw) + Constraint.__init__( + self, name=name, deferrable=deferrable, initially=initially, + info=info, **dialect_kw) self.onupdate = onupdate self.ondelete = ondelete self.link_to_name = link_to_name @@ -2575,14 +2580,12 @@ class ForeignKeyConstraint(Constraint): self.use_alter = use_alter self.match = match - self._elements = util.OrderedDict() - # standalone ForeignKeyConstraint - create # associated ForeignKey objects which will be applied to hosted # Column objects (in col.foreign_keys), either now or when attached # to the Table for string-specified names - for col, refcol in zip(columns, refcolumns): - self._elements[col] = ForeignKey( + self.elements = [ + ForeignKey( refcol, _constraint=self, name=self.name, @@ -2594,25 +2597,36 @@ class ForeignKeyConstraint(Constraint): deferrable=self.deferrable, initially=self.initially, **self.dialect_kwargs - ) + ) for refcol in refcolumns + ] + ColumnCollectionMixin.__init__(self, *columns) if table is not None: + if hasattr(self, "parent"): + assert table is self.parent self._set_parent_with_dispatch(table) - elif columns and \ - isinstance(columns[0], Column) and \ - columns[0].table is not None: - self._set_parent_with_dispatch(columns[0].table) + + def _append_element(self, column, fk): + self.columns.add(column) + self.elements.append(fk) + + @property + def _elements(self): + # legacy - provide a dictionary view of (column_key, fk) + return util.OrderedDict( + zip(self.column_keys, self.elements) + ) @property def _referred_schema(self): - for elem in self._elements.values(): + for elem in self.elements: return elem._referred_schema else: return None def _validate_dest_table(self, table): table_keys = set([elem._table_key() - for elem in self._elements.values()]) + for elem in self.elements]) if None not in table_keys and len(table_keys) > 1: elem0, elem1 = sorted(table_keys)[0:2] raise exc.ArgumentError( @@ -2625,38 +2639,48 @@ class ForeignKeyConstraint(Constraint): )) @property - def _col_description(self): - return ", ".join(self._elements) + def column_keys(self): + """Return a list of string keys representing the local + columns in this :class:`.ForeignKeyConstraint`. - @property - def columns(self): - return list(self._elements) + This list is either the original string arguments sent + to the constructor of the :class:`.ForeignKeyConstraint`, + or if the constraint has been initialized with :class:`.Column` + objects, is the string .key of each element. + + .. versionadded:: 1.0.0 + + """ + if hasattr(self, "parent"): + return self.columns.keys() + else: + return [ + col.key if isinstance(col, ColumnElement) + else str(col) for col in self._pending_colargs + ] @property - def elements(self): - return list(self._elements.values()) + def _col_description(self): + return ", ".join(self.column_keys) def _set_parent(self, table): - super(ForeignKeyConstraint, self)._set_parent(table) - - self._validate_dest_table(table) + Constraint._set_parent(self, table) - for col, fk in self._elements.items(): - # string-specified column names now get - # resolved to Column objects - if isinstance(col, util.string_types): - try: - col = table.c[col] - except KeyError: - raise exc.ArgumentError( - "Can't create ForeignKeyConstraint " - "on table '%s': no column " - "named '%s' is present." % (table.description, col)) + try: + ColumnCollectionConstraint._set_parent(self, table) + except KeyError as ke: + raise exc.ArgumentError( + "Can't create ForeignKeyConstraint " + "on table '%s': no column " + "named '%s' is present." % (table.description, ke.args[0])) + for col, fk in zip(self.columns, self.elements): if not hasattr(fk, 'parent') or \ fk.parent is not col: fk._set_parent_with_dispatch(col) + self._validate_dest_table(table) + if self.use_alter: def supports_alter(ddl, event, schema_item, bind, **kw): return table in set(kw['tables']) and \ @@ -2669,14 +2693,14 @@ class ForeignKeyConstraint(Constraint): def copy(self, schema=None, target_table=None, **kw): fkc = ForeignKeyConstraint( - [x.parent.key for x in self._elements.values()], + [x.parent.key for x in self.elements], [x._get_colspec( schema=schema, table_name=target_table.name if target_table is not None and x._table_key() == x.parent.table.key else None) - for x in self._elements.values()], + for x in self.elements], name=self.name, onupdate=self.onupdate, ondelete=self.ondelete, @@ -2687,8 +2711,8 @@ class ForeignKeyConstraint(Constraint): match=self.match ) for self_fk, other_fk in zip( - self._elements.values(), - fkc._elements.values()): + self.elements, + fkc.elements): self_fk._schema_item_copy(other_fk) return self._schema_item_copy(fkc) |