Support 'pyformat' style parameters in raw queries, Refs #10070

Add support for Oracle, fix an issue with the repr of RawQuerySet,
add tests and documentations. Also added a 'supports_paramstyle_pyformat'
database feature, True by default, False for SQLite.

Thanks Donald Stufft for review of documentation.

4 files changed, 52 insertions, 25 deletions

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 1a74232704..9abb9a9637 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -613,6 +613,11 @@ class BaseDatabaseFeatures(object):
     # when autocommit is disabled? http://bugs.python.org/issue8145#msg109965
     autocommits_when_autocommit_is_off = False
 
+    # Does the backend support 'pyformat' style ("... %(name)s ...", {'name': value})
+    # parameter passing? Note this can be provided by the backend even if not
+    # supported by the Python driver
+    supports_paramstyle_pyformat = True
+
     def __init__(self, connection):
         self.connection = connection
 
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index 3f39a15aa7..5e2b763f52 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -757,20 +757,37 @@ class FormatStylePlaceholderCursor(object):
         self.cursor.arraysize = 100
 
     def _format_params(self, params):
-        return tuple([OracleParam(p, self, True) for p in params])
+        try:
+            return dict((k,OracleParam(v, self, True)) for k,v in params.items())
+        except AttributeError:
+            return tuple([OracleParam(p, self, True) for p in params])
 
     def _guess_input_sizes(self, params_list):
-        sizes = [None] * len(params_list[0])
-        for params in params_list:
-            for i, value in enumerate(params):
-                if value.input_size:
-                    sizes[i] = value.input_size
-        self.setinputsizes(*sizes)
+        # Try dict handling; if that fails, treat as sequence
+        if hasattr(params_list[0], 'keys'):
+            sizes = {}
+            for params in params_list:
+                for k, value in params.items():
+                    if value.input_size:
+                        sizes[k] = value.input_size
+            self.setinputsizes(**sizes)
+        else:
+            # It's not a list of dicts; it's a list of sequences
+            sizes = [None] * len(params_list[0])
+            for params in params_list:
+                for i, value in enumerate(params):
+                    if value.input_size:
+                        sizes[i] = value.input_size
+            self.setinputsizes(*sizes)        
 
     def _param_generator(self, params):
-        return [p.force_bytes for p in params]
+        # Try dict handling; if that fails, treat as sequence
+        if hasattr(params, 'items'):
+            return dict((k, v.force_bytes) for k,v in params.items())
+        else:
+            return [p.force_bytes for p in params]
 
-    def execute(self, query, params=None):
+    def _fix_for_params(self, query, params):
         # cx_Oracle wants no trailing ';' for SQL statements.  For PL/SQL, it
         # it does want a trailing ';' but not a trailing '/'.  However, these
         # characters must be included in the original query in case the query
@@ -780,10 +797,18 @@ class FormatStylePlaceholderCursor(object):
         if params is None:
             params = []
             query = convert_unicode(query, self.charset)
+        elif hasattr(params, 'keys'):
+            # Handle params as dict
+            args = dict((k, ":%s"%k) for k in params.keys())
+            query = convert_unicode(query % args, self.charset)
         else:
-            params = self._format_params(params)
+            # Handle params as sequence
             args = [(':arg%d' % i) for i in range(len(params))]
             query = convert_unicode(query % tuple(args), self.charset)
+        return query, self._format_params(params)
+        
+    def execute(self, query, params=None):
+        query, params = self._fix_for_params(query, params)
         self._guess_input_sizes([params])
         try:
             return self.cursor.execute(query, self._param_generator(params))
@@ -794,22 +819,15 @@ class FormatStylePlaceholderCursor(object):
             raise
 
     def executemany(self, query, params=None):
-        # cx_Oracle doesn't support iterators, convert them to lists
-        if params is not None and not isinstance(params, (list, tuple)):
-            params = list(params)
-        try:
-            args = [(':arg%d' % i) for i in range(len(params[0]))]
-        except (IndexError, TypeError):
+        if not params:
             # No params given, nothing to do
             return None
-        # cx_Oracle wants no trailing ';' for SQL statements.  For PL/SQL, it
-        # it does want a trailing ';' but not a trailing '/'.  However, these
-        # characters must be included in the original query in case the query
-        # is being passed to SQL*Plus.
-        if query.endswith(';') or query.endswith('/'):
-            query = query[:-1]
-        query = convert_unicode(query % tuple(args), self.charset)
-        formatted = [self._format_params(i) for i in params]
+        # uniform treatment for sequences and iterables
+        params_iter = iter(params)
+        query, firstparams = self._fix_for_params(query, next(params_iter))
+        # we build a list of formatted params; as we're going to traverse it 
+        # more than once, we can't make it lazy by using a generator
+        formatted = [firstparams]+[self._format_params(p) for p in params_iter]
         self._guess_input_sizes(formatted)
         try:
             return self.cursor.executemany(query,
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 324adfd97b..92dbf354ae 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -101,6 +101,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_bulk_insert = True
     can_combine_inserts_with_and_without_auto_increment_pk = False
     autocommits_when_autocommit_is_off = True
+    supports_paramstyle_pyformat = False
 
     @cached_property
     def uses_savepoints(self):
diff --git a/django/db/models/query.py b/django/db/models/query.py
index b0ce25f5b5..27a87a3f65 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -1445,7 +1445,10 @@ class RawQuerySet(object):
             yield instance
 
     def __repr__(self):
-        return "<RawQuerySet: %r>" % (self.raw_query % tuple(self.params))
+        text = self.raw_query
+        if self.params:
+            text = text % (self.params if hasattr(self.params, 'keys') else tuple(self.params))
+        return "<RawQuerySet: %r>" % text
 
     def __getitem__(self, k):
         return list(self)[k]