Docs: Named parameters docs nad usage

Author: bgunebakan

docs/query.rst

@@ -54,6 +54,33 @@ characters appear, in the order they appear.
     Always use the parameter interpolation feature of the client library to
     guard against malicious input, as demonstrated in the example above.
 
+Named parameters
+----------------
+
+For queries with many parameters or repeated values, named parameters improve
+readability. Pass a :class:`py:dict` as the second argument using
+``%(name)s`` placeholders:
+
+    >>> cursor.execute(
+    ...     "INSERT INTO locations (name, date, kind, position) "
+    ...     "VALUES (%(name)s, %(date)s, %(kind)s, %(pos)s)",
+    ...     {"name": "Einstein Cross", "date": "2007-03-11", "kind": "Quasar", "pos": 7})
+
+The same parameter name may appear multiple times in the query:
+
+    >>> cursor.execute(
+    ...     "SELECT * FROM locations WHERE name = %(q)s OR kind = %(q)s",
+    ...     {"q": "Quasar"})
+
+The client converts the ``%(name)s`` placeholders to positional ``?`` markers
+before sending the query to CrateDB, so no server-side changes are required.
+
+.. NOTE::
+
+    Named parameters are not yet supported by ``executemany()``. Use
+    positional ``?`` placeholders with a :class:`py:list` of tuples for bulk
+    operations.
+
 Bulk inserts
 ------------