diff options
Diffstat (limited to 'django/db/models/sql/datastructures.py')
| -rw-r--r-- | django/db/models/sql/datastructures.py | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py index a245e451d6..1880f4558f 100644 --- a/django/db/models/sql/datastructures.py +++ b/django/db/models/sql/datastructures.py @@ -66,30 +66,40 @@ class Join(object): LEFT OUTER JOIN sometable ON sometable.somecol = othertable.othercol, params clause for this join. """ + join_conditions = [] params = [] - sql = [] - alias_str = '' if self.table_alias == self.table_name else (' %s' % self.table_alias) qn = compiler.quote_name_unless_alias qn2 = connection.ops.quote_name - sql.append('%s %s%s ON (' % (self.join_type, qn(self.table_name), alias_str)) + + # Add a join condition for each pair of joining columns. for index, (lhs_col, rhs_col) in enumerate(self.join_cols): - if index != 0: - sql.append(' AND ') - sql.append('%s.%s = %s.%s' % ( + join_conditions.append('%s.%s = %s.%s' % ( qn(self.parent_alias), qn2(lhs_col), qn(self.table_alias), qn2(rhs_col), )) + + # Add a single condition inside parentheses for whatever + # get_extra_restriction() returns. extra_cond = self.join_field.get_extra_restriction( compiler.query.where_class, self.table_alias, self.parent_alias) if extra_cond: extra_sql, extra_params = compiler.compile(extra_cond) - extra_sql = 'AND (%s)' % extra_sql + join_conditions.append('(%s)' % extra_sql) params.extend(extra_params) - sql.append('%s' % extra_sql) - sql.append(')') - return ' '.join(sql), params + + if not join_conditions: + # This might be a rel on the other end of an actual declared field. + declared_field = getattr(self.join_field, 'field', self.join_field) + raise ValueError( + "Join generated an empty ON clause. %s did not yield either " + "joining columns or extra restrictions." % declared_field.__class__ + ) + on_clause_sql = ' AND '.join(join_conditions) + alias_str = '' if self.table_alias == self.table_name else (' %s' % self.table_alias) + sql = '%s %s%s ON (%s)' % (self.join_type, qn(self.table_name), alias_str, on_clause_sql) + return sql, params def relabeled_clone(self, change_map): new_parent_alias = change_map.get(self.parent_alias, self.parent_alias) |