Fixed #35275 -- Fixed Meta.constraints validation crash on UniqueConstraint with OpClass().

This also introduces Expression.constraint_validation_compatible that
allows specifying that expression should be ignored during a constraint
validation.

2 files changed, 13 insertions, 0 deletions

diff --git a/docs/ref/models/expressions.txt b/docs/ref/models/expressions.txt
index 67baef7dfc..f630142294 100644
--- a/docs/ref/models/expressions.txt
+++ b/docs/ref/models/expressions.txt
@@ -1058,6 +1058,15 @@ calling the appropriate methods on the wrapped expression.
         Tells Django that this expression can be used in
         :attr:`Field.db_default`. Defaults to ``False``.
 
+    .. attribute:: constraint_validation_compatible
+
+        .. versionadded:: 5.1
+
+        Tells Django that this expression can be used during a constraint
+        validation. Expressions with ``constraint_validation_compatible`` set
+        to ``False`` must have only one source expression. Defaults to
+        ``True``.
+
     .. attribute:: contains_aggregate
 
         Tells Django that this expression contains an aggregate and that a
diff --git a/docs/releases/5.1.txt b/docs/releases/5.1.txt
index f2a6bccb0c..f068f3e96b 100644
--- a/docs/releases/5.1.txt
+++ b/docs/releases/5.1.txt
@@ -281,6 +281,10 @@ Models
   reload a model's value. This can be used to lock the row before reloading or
   to select related objects.
 
+* The new :attr:`.Expression.constraint_validation_compatible` attribute allows
+  specifying that the expression should be ignored during a constraint
+  validation.
+
 Requests and Responses
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