diff options
Diffstat (limited to 'lib/sqlalchemy/sql/expression.py')
| -rw-r--r-- | lib/sqlalchemy/sql/expression.py | 75 |
1 files changed, 57 insertions, 18 deletions
diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index d184816ab..5df3b8794 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -1269,10 +1269,15 @@ class ClauseElement(Visitable): return engine else: return None - + + @util.pending_deprecation('0.7', + 'Only SQL expressions which subclass ' + ':class:`.Executable` may provide the ' + ':func:`.execute` method.') def execute(self, *multiparams, **params): - """Compile and execute this :class:`ClauseElement`.""" - + """Compile and execute this :class:`ClauseElement`. + + """ e = self.bind if e is None: label = getattr(self, 'description', self.__class__.__name__) @@ -1284,9 +1289,13 @@ class ClauseElement(Visitable): raise exc.UnboundExecutionError(msg) return e._execute_clauseelement(self, multiparams, params) + @util.pending_deprecation('0.7', + 'Only SQL expressions which subclass ' + ':class:`.Executable` may provide the ' + ':func:`.scalar` method.') def scalar(self, *multiparams, **params): - """Compile and execute this :class:`ClauseElement`, returning the - result's scalar representation. + """Compile and execute this :class:`ClauseElement`, returning + the result's scalar representation. """ return self.execute(*multiparams, **params).scalar() @@ -1843,17 +1852,19 @@ class ColumnElement(ClauseElement, _CompareMixin): descending selectable. """ - - if name: - co = ColumnClause(name, selectable, type_=getattr(self, - 'type', None)) + if name is None: + name = self.anon_label + # TODO: may want to change this to anon_label, + # or some value that is more useful than the + # compiled form of the expression + key = str(self) else: - name = str(self) - co = ColumnClause(self.anon_label, selectable, - type_=getattr(self, 'type', None)) - + key = name + + co = ColumnClause(name, selectable, type_=getattr(self, + 'type', None)) co.proxies = [self] - selectable.columns[name] = co + selectable.columns[key] = co return co def compare(self, other, use_proxies=False, equivalents=None, **kw): @@ -2401,7 +2412,7 @@ class Executable(_Generative): COMMIT will be invoked in order to provide its "autocommit" feature. Typically, all INSERT/UPDATE/DELETE statements as well as CREATE/DROP statements have autocommit behavior enabled; SELECT - constructs do not. Use this option when invokving a SELECT or other + constructs do not. Use this option when invoking a SELECT or other specific SQL construct where COMMIT is desired (typically when calling stored procedures and such). @@ -2436,6 +2447,27 @@ class Executable(_Generative): """ self._execution_options = self._execution_options.union(kw) + def execute(self, *multiparams, **params): + """Compile and execute this :class:`.Executable`.""" + + e = self.bind + if e is None: + label = getattr(self, 'description', self.__class__.__name__) + msg = ('This %s is not bound and does not support direct ' + 'execution. Supply this statement to a Connection or ' + 'Engine for execution. Or, assign a bind to the statement ' + 'or the Metadata of its underlying tables to enable ' + 'implicit execution via this method.' % label) + raise exc.UnboundExecutionError(msg) + return e._execute_clauseelement(self, multiparams, params) + + def scalar(self, *multiparams, **params): + """Compile and execute this :class:`.Executable`, returning the + result's scalar representation. + + """ + return self.execute(*multiparams, **params).scalar() + # legacy, some outside users may be calling this _Executable = Executable @@ -3653,8 +3685,7 @@ class _ScalarSelect(_Grouping): def __init__(self, element): self.element = element - cols = list(element.c) - self.type = cols[0].type + self.type = element._scalar_type() @property def columns(self): @@ -3705,7 +3736,10 @@ class CompoundSelect(_SelectBaseMixin, FromClause): self.selects.append(s.self_group(self)) _SelectBaseMixin.__init__(self, **kwargs) - + + def _scalar_type(self): + return self.selects[0]._scalar_type() + def self_group(self, against=None): return _FromGrouping(self) @@ -3878,6 +3912,11 @@ class Select(_SelectBaseMixin, FromClause): return froms + def _scalar_type(self): + elem = self._raw_columns[0] + cols = list(elem._select_iterable) + return cols[0].type + @property def froms(self): """Return the displayed list of FromClause elements.""" |