From a5ede47f1225ac10e69e2624038424b013d6144f Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Thu, 11 Apr 2013 16:14:23 -0400 Subject: A major fix to the way in which a select() object produces labeled columns when apply_labels() is used; this mode produces a SELECT where each column is labeled as in _, to remove column name collisions for a multiple table select. The fix is that if two labels collide when combined with the table name, i.e. "foo.bar_id" and "foo_bar.id", anonymous aliasing will be applied to one of the dupes. This allows the ORM to handle both columns independently; previously, 0.7 would in some cases silently emit a second SELECT for the column that was "duped", and in 0.8 an ambiguous column error would be emitted. The "keys" applied to the .c. collection of the select() will also be deduped, so that the "column being replaced" warning will no longer emit for any select() that specifies use_labels, though the dupe key will be given an anonymous label which isn't generally user-friendly. [ticket:2702] --- lib/sqlalchemy/sql/compiler.py | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) (limited to 'lib/sqlalchemy/sql/compiler.py') diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py index 5a3a92a3e..b902f9ffc 100644 --- a/lib/sqlalchemy/sql/compiler.py +++ b/lib/sqlalchemy/sql/compiler.py @@ -992,13 +992,15 @@ class SQLCompiler(engine.Compiled): else: self.result_map[keyname] = name, objects, type_ - def _label_select_column(self, select, column, populate_result_map, + def _label_select_column(self, select, column, + populate_result_map, asfrom, column_clause_args, + name=None, within_columns_clause=True): """produce labeled columns present in a select().""" if column.type._has_column_expression and \ - populate_result_map: + populate_result_map: col_expr = column.type.column_expression(column) add_to_result_map = lambda keyname, name, objects, type_: \ self._add_to_result_map( @@ -1023,13 +1025,11 @@ class SQLCompiler(engine.Compiled): else: result_expr = col_expr - elif select is not None and \ - select.use_labels and \ - column._label: + elif select is not None and name: result_expr = _CompileLabel( col_expr, - column._label, - alt_names=(column._key_label, ) + name, + alt_names=(column._key_label,) ) elif \ @@ -1037,7 +1037,7 @@ class SQLCompiler(engine.Compiled): isinstance(column, sql.ColumnClause) and \ not column.is_literal and \ column.table is not None and \ - not isinstance(column.table, sql.Select): + not isinstance(column.table, sql.Select): result_expr = _CompileLabel(col_expr, sql._as_truncated(column.name), alt_names=(column.key,)) @@ -1098,11 +1098,11 @@ class SQLCompiler(engine.Compiled): # correlate_froms.union(existingfroms) populate_result_map = force_result_map or ( - compound_index == 0 and ( - not entry or \ - entry.get('iswrapper', False) - ) - ) + compound_index == 0 and ( + not entry or \ + entry.get('iswrapper', False) + ) + ) self.stack.append({'from': correlate_froms, 'iswrapper': iswrapper}) @@ -1117,10 +1117,12 @@ class SQLCompiler(engine.Compiled): # the actual list of columns to print in the SELECT column list. inner_columns = [ c for c in [ - self._label_select_column(select, column, + self._label_select_column(select, + column, populate_result_map, asfrom, - column_clause_args) - for column in util.unique_list(select.inner_columns) + column_clause_args, + name=name) + for name, column in select._columns_plus_names ] if c is not None ] -- cgit v1.2.1