Changed "exact" matches in MySQL to use the database's native collation.

This effectively reverses the change in [7798]. It was proving too difficult to
successfully manage all the side effects here and provide a satisfactory
solution for everybody. Many thanks to arne, Martin von Löwis and, particular,
Karen Tracey, for doing a lot of research and proto-patches here to establish what was possible and practical.

This is backwards incompatible if you were relying on the behaviour after
[7798]. The docs have been updated to indicate the solution.

Refs #2170, #7789, #8102.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8319 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/db-api.txt b/docs/db-api.txt
index b014a70b1e..ca7d47f8fa 100644
--- a/docs/db-api.txt
+++ b/docs/db-api.txt
@@ -1327,6 +1327,19 @@ changed in the development version. Previously, it was (intentionally)
 converted to ``WHERE id = NULL`` at the SQL level, which would never match
 anything. It has now been changed to behave the same as ``id__isnull=True``.
 
+.. admonition:: MySQL comparisons
+
+    In MySQL, whether or not ``exact`` comparisons are case-sensitive depends
+    upon the collation setting of the table involved. The default is usually
+    ``latin1_swedish_ci`` or ``utf8_swedish_ci``, which results in
+    case-insensitive comparisons. Change the collation to
+    ``latin1_swedish_cs`` or ``utf8_bin`` for case sensitive comparisons.
+
+    For more details, refer to the MySQL manual section about `character sets
+    and collations`_.
+
+.. _character sets and collations: http://dev.mysql.com/doc/refman/5.0/en/charset.html
+
 iexact
 ~~~~~~