From 5782c94f2382303dd28a35a9b9591ad480286220 Mon Sep 17 00:00:00 2001
From: Ramiro Morales <cramm0@gmail.com>
Date: Sat, 28 Dec 2013 18:00:16 -0300
Subject: [PATCH] Added generation of SQLite FK DDL in initial migrations.

SQLite accepts the relevant standard SQL (although by default it doesn't
enforce the constraint), and the 'traditional' creation backend helper
generate it, so this allows us to:

- Maintain the status quo
- Improve readability of the SQL code generated for that backend.

Also, we will need this for when we fix Refs #14204.
---
 django/db/backends/schema.py         | 31 +++++++++++++++++-----------
 django/db/backends/sqlite3/schema.py |  1 +
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/django/db/backends/schema.py b/django/db/backends/schema.py
index b26f41c89a..e690567738 100644
--- a/django/db/backends/schema.py
+++ b/django/db/backends/schema.py
@@ -52,6 +52,7 @@ class BaseDatabaseSchemaEditor(object):
     sql_delete_unique = "ALTER TABLE %(table)s DROP CONSTRAINT %(name)s"
 
     sql_create_fk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s FOREIGN KEY (%(column)s) REFERENCES %(to_table)s (%(to_column)s) DEFERRABLE INITIALLY DEFERRED"
+    sql_create_inline_fk = None
     sql_delete_fk = "ALTER TABLE %(table)s DROP CONSTRAINT %(name)s"
 
     sql_create_index = "CREATE INDEX %(name)s ON %(table)s (%(columns)s)%(extra)s"
@@ -189,11 +190,6 @@ class BaseDatabaseSchemaEditor(object):
             col_type_suffix = field.db_type_suffix(connection=self.connection)
             if col_type_suffix:
                 definition += " %s" % col_type_suffix
-            # Add the SQL to our big list
-            column_sqls.append("%s %s" % (
-                self.quote_name(field.column),
-                definition,
-            ))
             params.extend(extra_params)
             # Indexes
             if field.db_index and not field.unique:
@@ -206,18 +202,29 @@ class BaseDatabaseSchemaEditor(object):
                     }
                 )
             # FK
-            if field.rel and self.connection.features.supports_foreign_keys:
+            if field.rel:
                 to_table = field.rel.to._meta.db_table
                 to_column = field.rel.to._meta.get_field(field.rel.field_name).column
-                self.deferred_sql.append(
-                    self.sql_create_fk % {
-                        "name": self._create_index_name(model, [field.column], suffix="_fk_%s_%s" % (to_table, to_column)),
-                        "table": self.quote_name(model._meta.db_table),
-                        "column": self.quote_name(field.column),
+                if self.connection.features.supports_foreign_keys:
+                    self.deferred_sql.append(
+                        self.sql_create_fk % {
+                            "name": self._create_index_name(model, [field.column], suffix="_fk_%s_%s" % (to_table, to_column)),
+                            "table": self.quote_name(model._meta.db_table),
+                            "column": self.quote_name(field.column),
+                            "to_table": self.quote_name(to_table),
+                            "to_column": self.quote_name(to_column),
+                        }
+                    )
+                elif self.sql_create_inline_fk:
+                    definition += " " + self.sql_create_inline_fk % {
                         "to_table": self.quote_name(to_table),
                         "to_column": self.quote_name(to_column),
                     }
-                )
+            # Add the SQL to our big list
+            column_sqls.append("%s %s" % (
+                self.quote_name(field.column),
+                definition,
+            ))
             # Autoincrement SQL (for backends with post table definition variant)
             if field.get_internal_type() == "AutoField":
                 autoinc_sql = self.connection.ops.autoinc_sql(model._meta.db_table, field.column)
diff --git a/django/db/backends/sqlite3/schema.py b/django/db/backends/sqlite3/schema.py
index 3196b48946..41391724f6 100644
--- a/django/db/backends/sqlite3/schema.py
+++ b/django/db/backends/sqlite3/schema.py
@@ -6,6 +6,7 @@ from django.db.models.fields.related import ManyToManyField
 class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
 
     sql_delete_table = "DROP TABLE %(table)s"
+    sql_create_inline_fk = "REFERENCES %(to_table)s (%(to_column)s)"
 
     def _remake_table(self, model, create_fields=[], delete_fields=[], alter_fields=[], rename_fields=[], override_uniques=None):
         """