How can I resolve errors encountered during migration from SQLit

ghz 9months ago ⋅ 71 views

How can I resolve errors encountered during migration from SQLite to MySQL in Django?

(venv) PS E:\Easyalgo project\django-tailwind-blog> python manage.py migrate
System check identified some issues:

WARNINGS:
?: (ckeditor.W001) django-ckeditor bundles CKEditor 4.22.1 which isn't supported anmyore and which does have unfixed security issues, see for example https://ckeditor.com/cke4/release/CKEditor-4.24.0-LTS . You should consider strongly switching to a different editor (maybe CKEditor 5 respectively django-ckeditor-5 after checking whether the CKEditor 5 license terms work for you) or switch to the non-free CKEditor 4 LTS package. See https://ckeditor.com/ckeditor-4-support/ for more on this. (Note! This notice has been added by the django-ckeditor developers and we are not affiliated with CKSource and were not involved in the licensing change, so please refrain from complaining to us. Thanks.)
?: (urls.W002) Your URL pattern '/post' has a route beginning with a '/'. Remove this slash as it is unnecessary. If this pattern is targeted in an include(), ensure the include() pattern has a trailing '/'.
Operations to perform:
  Apply all migrations: Adv_css, DBMS, admin, auth, blogs, contenttypes, cp_sheet, cs_subject, home, htmlapp, mini_sheet, networking, patterns, prepration_sheet, programming, sessions, stl
Running migrations:
  Applying home.0003_blog_remark...Traceback (most recent call last):
  File "E:\Easyalgo project\django-tailwind-blog\venv\Lib\site-packages\django\db\backends\utils.py", line 105, in _execute
    return self.cursor.execute(sql, params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\Easyalgo project\django-tailwind-blog\venv\Lib\site-packages\django\db\backends\mysql\base.py", line 76, in execute
    return self.cursor.execute(query, args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\Easyalgo project\django-tailwind-blog\venv\Lib\site-packages\MySQLdb\cursors.py", line 179, in execute
    res = self._query(mogrified_query)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "E:\Easyalgo project\django-tailwind-blog\venv\Lib\site-packages\MySQLdb\cursors.py", line 330, in _query
    db.query(q)
File "E:\Easyalgo project\django-tailwind-blog\venv\Lib\site-packages\MySQLdb\connections.py", line 261, in query
    _mysql.connection.query(self, query)
MySQLdb.OperationalError: (1170, "BLOB/TEXT column 'remark' used in key specification without a key length")

Answers

The error you're encountering during the migration from SQLite to MySQL in Django is related to a column called remark in your home_blog table. The error message indicates that there is an issue with the column being used in a key specification without a key length.

This error occurs because MySQL requires you to specify a length for any index that includes a TEXT or BLOB column. In your case, it seems like you're trying to create an index on the remark column, which is of type TEXT or BLOB, without specifying a key length.

To resolve this issue, you can either remove the index on the remark column or specify a key length for it. Here's how you can do it:

  1. Remove the Index (Not Recommended if Index is Necessary): If the index on the remark column is not necessary, you can remove it. You can do this by removing the relevant migration file that creates the index or by manually editing the migration file to remove the index creation operation.

  2. Specify a Key Length: If the index on the remark column is necessary, you need to specify a key length for it. You can do this by modifying the migration file that creates the index and specifying a key length for the index.

    For example, if you're using Django's models.TextField for the remark column, you can specify a key length for the index in the migration file like this:

    operations = [
    migrations.AlterField(
        model_name='home_blog',
        name='remark',
        field=models.TextField(),
    ),
    migrations.RunSQL(
        sql='CREATE INDEX idx_remark ON home_blog (remark(255));',
        reverse_sql='DROP INDEX idx_remark ON home_blog;',
    ),
]

    In this example, 255 is the key length specified for the index on the remark column.

After making the necessary changes, you can rerun the migration to apply the changes to the database. Make sure to test your application thoroughly after making these changes to ensure that everything is working as expected.

#mysql