diff --git a/docs/ref/databases.txt b/docs/ref/databases.txt index 96829724b5..831d32170a 100644 --- a/docs/ref/databases.txt +++ b/docs/ref/databases.txt @@ -571,11 +571,13 @@ query for ``WHERE mycolumn=0``, both rows will match. Similarly, ``WHERE mycolum will match the value ``'abc1'``. Therefore, string type fields included in Django will always cast the value to a string before using it in a query. -If you implement custom model fields that inherit from :class:`~django.db.models.Field` -directly, are overriding :meth:`~django.db.models.Field.get_prep_value`, or use -:meth:`extra() ` or -:meth:`raw() `, you should ensure that you -perform the appropriate typecasting. +If you implement custom model fields that inherit from +:class:`~django.db.models.Field` directly, are overriding +:meth:`~django.db.models.Field.get_prep_value`, or use +:class:`~django.db.models.expressions.RawSQL`, +:meth:`~django.db.models.query.QuerySet.extra`, or +:meth:`~django.db.models.Manager.raw`, you should ensure that you perform +appropriate typecasting. .. _sqlite-notes: diff --git a/docs/ref/models/expressions.txt b/docs/ref/models/expressions.txt index 29ee59a29d..e114fb56ed 100644 --- a/docs/ref/models/expressions.txt +++ b/docs/ref/models/expressions.txt @@ -391,6 +391,33 @@ Conditional expressions allow you to use :keyword:`if` ... :keyword:`elif` ... :keyword:`else` logic in queries. Django natively supports SQL ``CASE`` expressions. For more details see :doc:`conditional-expressions`. +Raw SQL expressions +------------------- + +.. versionadded:: 1.8 + +.. currentmodule:: django.db.models.expressions + +.. class:: RawSQL(sql, params, output_field=None) + +Sometimes database expressions can't easily express a complex ``WHERE`` clause. +In these edge cases, use the ``RawSQL`` expression. For example:: + + >>> from django.db.models.expressions import RawSQL + >>> queryset.annotate(val=RawSQL("select col from sometable where othercol = %s", (someparam,))) + +These extra lookups may not be portable to different database engines (because +you're explicitly writing SQL code) and violate the DRY principle, so you +should avoid them if possible. + +.. warning:: + + You should be very careful to escape any parameters that the user can + control by using ``params`` in order to protect against :ref:`SQL injection + attacks `. + +.. currentmodule:: django.db.models + Technical Information ===================== diff --git a/docs/topics/security.txt b/docs/topics/security.txt index 6eab39efed..3d535bb85e 100644 --- a/docs/topics/security.txt +++ b/docs/topics/security.txt @@ -94,7 +94,8 @@ write :ref:`raw queries ` or execute :ref:`custom sql `. These capabilities should be used sparingly and you should always be careful to properly escape any parameters that the user can control. In addition, you should exercise caution when using -:meth:`extra() `. +:meth:`~django.db.models.query.QuerySet.extra` and +:class:`~django.db.models.expressions.RawSQL`. Clickjacking protection =======================