diff options
Diffstat (limited to 'lib/sqlalchemy/sql/util.py')
| -rw-r--r-- | lib/sqlalchemy/sql/util.py | 172 |
1 files changed, 157 insertions, 15 deletions
diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py index fbbe15da3..5f180646c 100644 --- a/lib/sqlalchemy/sql/util.py +++ b/lib/sqlalchemy/sql/util.py @@ -1,5 +1,5 @@ # sql/util.py -# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors +# Copyright (C) 2005-2016 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under @@ -16,7 +16,8 @@ from itertools import chain from collections import deque from .elements import BindParameter, ColumnClause, ColumnElement, \ - Null, UnaryExpression, literal_column, Label, _label_reference + Null, UnaryExpression, literal_column, Label, _label_reference, \ + _textual_label_reference from .selectable import ScalarSelect, Join, FromClause, FromGrouping from .schema import Column @@ -153,6 +154,7 @@ def unwrap_order_by(clause): without DESC/ASC/NULLS FIRST/NULLS LAST""" cols = util.column_set() + result = [] stack = deque([clause]) while stack: t = stack.popleft() @@ -163,11 +165,37 @@ def unwrap_order_by(clause): ): if isinstance(t, _label_reference): t = t.element - cols.add(t) + if isinstance(t, (_textual_label_reference)): + continue + if t not in cols: + cols.add(t) + result.append(t) else: for c in t.get_children(): stack.append(c) - return cols + return result + + +def expand_column_list_from_order_by(collist, order_by): + """Given the columns clause and ORDER BY of a selectable, + return a list of column expressions that can be added to the collist + corresponding to the ORDER BY, without repeating those already + in the collist. + + """ + cols_already_present = set([ + col.element if col._order_by_label_element is not None + else col for col in collist + ]) + + return [ + col for col in + chain(*[ + unwrap_order_by(o) + for o in order_by + ]) + if col not in cols_already_present + ] def clause_is_present(clause, search): @@ -197,6 +225,21 @@ def surface_selectables(clause): stack.append(elem.element) +def surface_column_elements(clause): + """traverse and yield only outer-exposed column elements, such as would + be addressable in the WHERE clause of a SELECT if this element were + in the columns clause.""" + + stack = deque([clause]) + while stack: + elem = stack.popleft() + yield elem + for sub in elem.get_children(): + if isinstance(sub, FromGrouping): + continue + stack.append(sub) + + def selectables_overlap(left, right): """Return True if left/right have some overlapping selectable""" @@ -236,28 +279,128 @@ def _quote_ddl_expr(element): return repr(element) -class _repr_params(object): - """A string view of bound parameters, truncating - display to the given number of 'multi' parameter sets. +class _repr_base(object): + _LIST = 0 + _TUPLE = 1 + _DICT = 2 + + __slots__ = 'max_chars', + + def trunc(self, value): + rep = repr(value) + lenrep = len(rep) + if lenrep > self.max_chars: + segment_length = self.max_chars // 2 + rep = ( + rep[0:segment_length] + + (" ... (%d characters truncated) ... " + % (lenrep - self.max_chars)) + + rep[-segment_length:] + ) + return rep + + +class _repr_row(_repr_base): + """Provide a string view of a row.""" + + __slots__ = 'row', + + def __init__(self, row, max_chars=300): + self.row = row + self.max_chars = max_chars + + def __repr__(self): + trunc = self.trunc + return "(%s%s)" % ( + ", ".join(trunc(value) for value in self.row), + "," if len(self.row) == 1 else "" + ) + + +class _repr_params(_repr_base): + """Provide a string view of bound parameters. + + Truncates display to a given numnber of 'multi' parameter sets, + as well as long values to a given number of characters. """ - def __init__(self, params, batches): + __slots__ = 'params', 'batches', + + def __init__(self, params, batches, max_chars=300): self.params = params self.batches = batches + self.max_chars = max_chars def __repr__(self): - if isinstance(self.params, (list, tuple)) and \ - len(self.params) > self.batches and \ - isinstance(self.params[0], (list, dict, tuple)): + if isinstance(self.params, list): + typ = self._LIST + ismulti = self.params and isinstance( + self.params[0], (list, dict, tuple)) + elif isinstance(self.params, tuple): + typ = self._TUPLE + ismulti = self.params and isinstance( + self.params[0], (list, dict, tuple)) + elif isinstance(self.params, dict): + typ = self._DICT + ismulti = False + else: + return self.trunc(self.params) + + if ismulti and len(self.params) > self.batches: msg = " ... displaying %i of %i total bound parameter sets ... " return ' '.join(( - repr(self.params[:self.batches - 2])[0:-1], + self._repr_multi(self.params[:self.batches - 2], typ)[0:-1], msg % (self.batches, len(self.params)), - repr(self.params[-2:])[1:] + self._repr_multi(self.params[-2:], typ)[1:] )) + elif ismulti: + return self._repr_multi(self.params, typ) else: - return repr(self.params) + return self._repr_params(self.params, typ) + + def _repr_multi(self, multi_params, typ): + if multi_params: + if isinstance(multi_params[0], list): + elem_type = self._LIST + elif isinstance(multi_params[0], tuple): + elem_type = self._TUPLE + elif isinstance(multi_params[0], dict): + elem_type = self._DICT + else: + assert False, \ + "Unknown parameter type %s" % (type(multi_params[0])) + + elements = ", ".join( + self._repr_params(params, elem_type) + for params in multi_params) + else: + elements = "" + + if typ == self._LIST: + return "[%s]" % elements + else: + return "(%s)" % elements + + def _repr_params(self, params, typ): + trunc = self.trunc + if typ is self._DICT: + return "{%s}" % ( + ", ".join( + "%r: %s" % (key, trunc(value)) + for key, value in params.items() + ) + ) + elif typ is self._TUPLE: + return "(%s%s)" % ( + ", ".join(trunc(value) for value in params), + "," if len(params) == 1 else "" + + ) + else: + return "[%s]" % ( + ", ".join(trunc(value) for value in params) + ) def adapt_criterion_to_null(crit, nulls): @@ -430,7 +573,6 @@ def criterion_as_pairs(expression, consider_as_foreign_keys=None, return pairs - class ClauseAdapter(visitors.ReplacingCloningVisitor): """Clones and modifies clauses based on column correspondence. |