Fixed #32672 -- Fixed introspection of primary key constraints on SQLite.

Thanks Simon Charette for the implementation idea.

django/db/backends/sqlite3/introspection.py

@@ -201,25 +201,12 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
 
     def get_primary_key_column(self, cursor, table_name):
         """Return the column name of the primary key for the given table."""
-        # Don't use PRAGMA because that causes issues with some transactions
         cursor.execute(
-            "SELECT sql, type FROM sqlite_master "
-            "WHERE tbl_name = %s AND type IN ('table', 'view')",
-            [table_name]
+            'PRAGMA table_info(%s)' % self.connection.ops.quote_name(table_name)
         )
-        row = cursor.fetchone()
-        if row is None:
-            raise ValueError("Table %s does not exist" % table_name)
-        create_sql, table_type = row
-        if table_type == 'view':
-            # Views don't have a primary key.
-            return None
-        fields_sql = create_sql[create_sql.index('(') + 1:create_sql.rindex(')')]
-        for field_desc in fields_sql.split(','):
-            field_desc = field_desc.strip()
-            m = re.match(r'(?:(?:["`\[])(.*)(?:["`\]])|(\w+)).*PRIMARY KEY.*', field_desc)
-            if m:
-                return m[1] if m[1] else m[2]
+        for _, name, *_, pk in cursor.fetchall():
+            if pk:
+                return name
         return None
 
     def _get_foreign_key_constraints(self, cursor, table_name):

tests/backends/sqlite/test_introspection.py

@@ -28,6 +28,25 @@ class IntrospectionTests(TestCase):
                     finally:
                         cursor.execute('DROP TABLE test_primary')
 
+    def test_get_primary_key_column_pk_constraint(self):
+        sql = """
+            CREATE TABLE test_primary(
+                id INTEGER NOT NULL,
+                created DATE,
+                PRIMARY KEY(id)
+            )
+        """
+        with connection.cursor() as cursor:
+            try:
+                cursor.execute(sql)
+                field = connection.introspection.get_primary_key_column(
+                    cursor,
+                    'test_primary',
+                )
+                self.assertEqual(field, 'id')
+            finally:
+                cursor.execute('DROP TABLE test_primary')
+
 
 @unittest.skipUnless(connection.vendor == 'sqlite', 'SQLite tests')
 class ParsingTests(TestCase):