Initial commit. Basic models mostly done.

venv/lib/python3.8/site-packages/django/db/backends/mysql/validation.py

@@ -0,0 +1,60 @@
+from django.core import checks
+from django.db.backends.base.validation import BaseDatabaseValidation
+from django.utils.version import get_docs_version
+
+
+class DatabaseValidation(BaseDatabaseValidation):
+    def check(self, **kwargs):
+        issues = super().check(**kwargs)
+        issues.extend(self._check_sql_mode(**kwargs))
+        return issues
+
+    def _check_sql_mode(self, **kwargs):
+        with self.connection.cursor() as cursor:
+            cursor.execute("SELECT @@sql_mode")
+            sql_mode = cursor.fetchone()
+        modes = set(sql_mode[0].split(',') if sql_mode else ())
+        if not (modes & {'STRICT_TRANS_TABLES', 'STRICT_ALL_TABLES'}):
+            return [checks.Warning(
+                "MySQL Strict Mode is not set for database connection '%s'" % self.connection.alias,
+                hint="MySQL's Strict Mode fixes many data integrity problems in MySQL, "
+                     "such as data truncation upon insertion, by escalating warnings into "
+                     "errors. It is strongly recommended you activate it. See: "
+                     "https://docs.djangoproject.com/en/%s/ref/databases/#mysql-sql-mode"
+                     % (get_docs_version(),),
+                id='mysql.W002',
+            )]
+        return []
+
+    def check_field_type(self, field, field_type):
+        """
+        MySQL has the following field length restriction:
+        No character (varchar) fields can have a length exceeding 255
+        characters if they have a unique index on them.
+        MySQL doesn't support a database index on some data types.
+        """
+        errors = []
+        if (field_type.startswith('varchar') and field.unique and
+                (field.max_length is None or int(field.max_length) > 255)):
+            errors.append(
+                checks.Error(
+                    'MySQL does not allow unique CharFields to have a max_length > 255.',
+                    obj=field,
+                    id='mysql.E001',
+                )
+            )
+
+        if field.db_index and field_type.lower() in self.connection._limited_data_types:
+            errors.append(
+                checks.Warning(
+                    '%s does not support a database index on %s columns.'
+                    % (self.connection.display_name, field_type),
+                    hint=(
+                        "An index won't be created. Silence this warning if "
+                        "you don't care about it."
+                    ),
+                    obj=field,
+                    id='fields.W162',
+                )
+            )
+        return errors