[4.2.x] Fixed #34320 -- Make sure constraints names are obtained from truncated columns names.

Backport of 6bdc3c58b65eb32fd63cd41849f00a17a36b4473 from main

1 files changed, 6 insertions, 2 deletions

diff --git a/django/db/backends/base/schema.py b/django/db/backends/base/schema.py
index 3a83e14be9..070211f6d2 100644
--- a/django/db/backends/base/schema.py
+++ b/django/db/backends/base/schema.py
@@ -11,7 +11,7 @@ from django.db.backends.ddl_references import (
     Statement,
     Table,
 )
-from django.db.backends.utils import names_digest, split_identifier
+from django.db.backends.utils import names_digest, split_identifier, truncate_name
 from django.db.models import Deferrable, Index
 from django.db.models.sql import Query
 from django.db.transaction import TransactionManagementError, atomic
@@ -1760,7 +1760,11 @@ class BaseDatabaseSchemaEditor:
         """Return all constraint names matching the columns and conditions."""
         if column_names is not None:
             column_names = [
-                self.connection.introspection.identifier_converter(name)
+                self.connection.introspection.identifier_converter(
+                    truncate_name(name, self.connection.ops.max_name_length())
+                )
+                if self.connection.features.truncates_names
+                else self.connection.introspection.identifier_converter(name)
                 for name in column_names
             ]
         with self.connection.cursor() as cursor: