From 9f894d2f265bb5fd03ab0b3aa3fd164108c99259 Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Wed, 5 Nov 2008 20:50:48 +0000 Subject: - Dialects can now generate label names of adjustable length. Pass in the argument "label_length=" to create_engine() to adjust how many characters max will be present in dynamically generated column labels, i.e. "somecolumn AS somelabel". Any value less than 6 will result in a label of minimal size, consiting of an underscore and a numeric counter. The compiler uses the value of dialect.max_identifier_length as a default. [ticket:1211] - removed ANON_NAME regular expression, using string patterns now - _generated_label() unicode subclass is used to indicate generated names which are subject to truncation --- lib/sqlalchemy/sql/expression.py | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'lib/sqlalchemy/sql/expression.py') diff --git a/lib/sqlalchemy/sql/expression.py b/lib/sqlalchemy/sql/expression.py index 3b996d6cb..85f229ba0 100644 --- a/lib/sqlalchemy/sql/expression.py +++ b/lib/sqlalchemy/sql/expression.py @@ -869,6 +869,9 @@ func = _FunctionGenerator() # TODO: use UnaryExpression for this instead ? modifier = _FunctionGenerator(group=False) +class _generated_label(unicode): + """A unicode subclass used to identify dynamically generated names.""" + def _clone(element): return element._clone() @@ -1607,7 +1610,7 @@ class ColumnElement(ClauseElement, _CompareMixin): expressions and function calls. """ - return "{ANON %d %s}" % (id(self), getattr(self, 'name', 'anon')) + return _generated_label("%%(%d %s)s" % (id(self), getattr(self, 'name', 'anon'))) class ColumnCollection(util.OrderedProperties): """An ordered dictionary that stores a list of ColumnElement @@ -1908,9 +1911,9 @@ class _BindParamClause(ColumnElement): """ if unique: - self.key = "{ANON %d %s}" % (id(self), key or 'param') + self.key = _generated_label("%%(%d %s)s" % (id(self), key or 'param')) else: - self.key = key or "{ANON %d param}" % id(self) + self.key = key or _generated_label("%%(%d param)s" % id(self)) self._orig_key = key or 'param' self.unique = unique self.value = value @@ -1927,13 +1930,13 @@ class _BindParamClause(ColumnElement): def _clone(self): c = ClauseElement._clone(self) if self.unique: - c.key = "{ANON %d %s}" % (id(c), c._orig_key or 'param') + c.key = _generated_label("%%(%d %s)s" % (id(c), c._orig_key or 'param')) return c def _convert_to_unique(self): if not self.unique: self.unique = True - self.key = "{ANON %d %s}" % (id(self), self._orig_key or 'param') + self.key = _generated_label("%%(%d %s)s" % (id(self), self._orig_key or 'param')) def _get_from_objects(self, **modifiers): return [] @@ -2518,7 +2521,7 @@ class Alias(FromClause): if alias is None: if self.original.named_with_column: alias = getattr(self.original, 'name', None) - alias = '{ANON %d %s}' % (id(self), alias or 'anon') + alias = _generated_label('%%(%d %s)s' % (id(self), alias or 'anon')) self.name = alias @property @@ -2637,7 +2640,7 @@ class _Label(ColumnElement): def __init__(self, name, element, type_=None): while isinstance(element, _Label): element = element.element - self.name = self.key = self._label = name or "{ANON %d %s}" % (id(self), getattr(element, 'name', 'anon')) + self.name = self.key = self._label = name or _generated_label("%%(%d %s)s" % (id(self), getattr(element, 'name', 'anon'))) self._element = element self._type = type_ self.quote = element.quote @@ -2736,7 +2739,7 @@ class _ColumnClause(_Immutable, ColumnElement): _label = label + "_" + str(counter) counter += 1 label = _label - return label + return _generated_label(label) else: return self.name -- cgit v1.2.1