Comment failed to work after deployment?

[JTP-123]

I have tried to deploy my personal blog on a host-free webiste called PythonAnywhere, But after deployment, I found that I can not comment and visit file html tag. I am not familiar with alembic, thus I come to community for help.
Here is what effort I made:
At first, the question is that I can not log in after deployment on PythonAnywhere. I used flask db migrate on backend:

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
ERROR [flask_migrate] Error: Target database is not up to date.

I guess the problem is current migration edition is not consistent with head mirgation edition, so i did this although i don't know why two different editions happened:

>>>flask db heads
ceca8f22389c (head)
>>>flask db current
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
dc96d9b0d0bf

I then use flask db stamp heads to mark the migration edition:

flask db stamp heads
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running stamp_revision dc96d9b0d0bf -> ceca8f22389c

And check it:

flask db current
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
ceca8f22389c (head)

then run:

flask db upgrade
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.

but it seems still not work, so i run command again:

flask db migrate
    INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
    INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
    INFO  [alembic.autogenerate.compare] Detected added table 'message'
    INFO  [alembic.autogenerate.compare] Detected added index 'ix_message_timestamp' on '['timestamp']'
    INFO  [alembic.autogenerate.compare] Detected added table 'notification'
    INFO  [alembic.autogenerate.compare] Detected added index 'ix_notification_name' on '['name']'
    INFO  [alembic.autogenerate.compare] Detected added index 'ix_notification_timestamp' on '['timestamp']'
    INFO  [alembic.autogenerate.compare] Detected added table 'comment'
    INFO  [alembic.autogenerate.compare] Detected added index 'ix_comment_timestamp' on '['timestamp']'
    INFO  [alembic.autogenerate.compare] Detected added column 'post.language'
    INFO  [alembic.autogenerate.compare] Detected added column 'post.body_html'
    INFO  [alembic.autogenerate.compare] Detected type change from VARCHAR(length=140) to Text() on 'post.body'
    INFO  [alembic.autogenerate.compare] Detected added column 'user.token'
    INFO  [alembic.autogenerate.compare] Detected added column 'user.token_expiration'
    INFO  [alembic.autogenerate.compare] Detected added column 'user.last_message_read_time'
    INFO  [alembic.autogenerate.compare] Detected added index 'ix_user_token' on '['token']'
      Generating /home/JTPing/microblog/migrations/versions/e6990a7ae19f_.py ...  done

(venv) 01:50 ~/microblog (main)$ flask db upgrade
    INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
    INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
    INFO  [alembic.runtime.migration] Running upgrade 9d026987d6f2 -> e6990a7ae19f, empty message

It works and i can log in now, but unexpected things occurs: all previous user data is gone , so i registered again, but i find that i can't not comment and the error is same as the above "The administrator has been notified. Sorry for the inconvenience!" Also, i clicked the file tag, the error was same. i do not know why.

I used cd migrations/versions and ls to list all subfile:

05eba44a406a_notifications.py             b07ebb5fe6e0_fix_markdown_rendering_of_comments.py
14ba2865cec3_add_comments.py              ceca8f22389c_user_tokens.py
3d95c0a8c088_users_table.py               dc96d9b0d0bf_followers.py
6ee987d26551_posts_table.py               e6990a7ae19f_.py
92a7096214ea_new_fields_in_user_model.py  e949960c17e9_let_user_be_able_to_follow_and_unfollow.py
9389414e987c_enable_markdown_editor.py    f3cff53a2dcf_add_language_to_posts.py
9d026987d6f2_.py                          fd8a7d4f9bd4_private_messages.py
__pycache__

Compare the above with my local file, I found two extra file e6990a7ae19f_.py and 9d026987d6f2_.py, and the latter is the last version which produced logging problems, the former is now database stand on.

I guess the problem lies in the last generated migrations file: e6990a7ae19f_.py , so I cat it.

"""empty message
Revision ID: e6990a7ae19f
Revises: 9d026987d6f2
Create Date: 2023-12-09 01:50:25.406017
"""
from alembic import op
import sqlalchemy as sa
# revision identifiers, used by Alembic.
revision = 'e6990a7ae19f'
down_revision = '9d026987d6f2'
branch_labels = None
depends_on = None
def upgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    op.create_table('message',
    sa.Column('id', sa.Integer(), nullable=False),
    sa.Column('sender_id', sa.Integer(), nullable=True),
    sa.Column('recipient_id', sa.Integer(), nullable=True),
    sa.Column('body', sa.String(length=140), nullable=True),
    sa.Column('timestamp', sa.DateTime(), nullable=True),
    sa.ForeignKeyConstraint(['recipient_id'], ['user.id'], ),
    sa.ForeignKeyConstraint(['sender_id'], ['user.id'], ),
    sa.PrimaryKeyConstraint('id')
    )
    with op.batch_alter_table('message', schema=None) as batch_op:
        batch_op.create_index(batch_op.f('ix_message_timestamp'), ['timestamp'], unique=False)
    op.create_table('notification',
    sa.Column('id', sa.Integer(), nullable=False),
    sa.Column('name', sa.String(length=128), nullable=True),
    sa.Column('user_id', sa.Integer(), nullable=True),
    sa.Column('timestamp', sa.Float(), nullable=True),
    sa.Column('payload_json', sa.Text(), nullable=True),
    sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
    sa.PrimaryKeyConstraint('id')
    )
    with op.batch_alter_table('notification', schema=None) as batch_op:
        batch_op.create_index(batch_op.f('ix_notification_name'), ['name'], unique=False)
        batch_op.create_index(batch_op.f('ix_notification_timestamp'), ['timestamp'], unique=False)
    op.create_table('comment',
    sa.Column('id', sa.Integer(), nullable=False),
    sa.Column('body', sa.String(length=140), nullable=True),
    sa.Column('timestamp', sa.DateTime(), nullable=True),
    sa.Column('user_id', sa.Integer(), nullable=True),
    sa.Column('post_id', sa.Integer(), nullable=True),
    sa.Column('body_html', sa.Text(), nullable=True),
    sa.ForeignKeyConstraint(['post_id'], ['post.id'], ),
    sa.ForeignKeyConstraint(['user_id'], ['user.id'], ),
    sa.PrimaryKeyConstraint('id')
    )
    with op.batch_alter_table('comment', schema=None) as batch_op:
        batch_op.create_index(batch_op.f('ix_comment_timestamp'), ['timestamp'], unique=False)
    with op.batch_alter_table('post', schema=None) as batch_op:
        batch_op.add_column(sa.Column('language', sa.String(length=5), nullable=True))
        batch_op.add_column(sa.Column('body_html', sa.Text(), nullable=True))
        batch_op.alter_column('body',
               existing_type=sa.VARCHAR(length=140),
               type_=sa.Text(),
               existing_nullable=True)
    with op.batch_alter_table('user', schema=None) as batch_op:
        batch_op.add_column(sa.Column('token', sa.String(length=32), nullable=True))
        batch_op.add_column(sa.Column('token_expiration', sa.DateTime(), nullable=True))
        batch_op.add_column(sa.Column('last_message_read_time', sa.DateTime(), nullable=True))
        batch_op.create_index(batch_op.f('ix_user_token'), ['token'], unique=True)
       # ### end Alembic commands ###
def downgrade():
    # ### commands auto generated by Alembic - please adjust! ###
    with op.batch_alter_table('user', schema=None) as batch_op:
        batch_op.drop_index(batch_op.f('ix_user_token'))
        batch_op.drop_column('last_message_read_time')
        batch_op.drop_column('token_expiration')
        batch_op.drop_column('token')
    with op.batch_alter_table('post', schema=None) as batch_op:
        batch_op.alter_column('body',
               existing_type=sa.Text(),
               type_=sa.VARCHAR(length=140),
               existing_nullable=True)
        batch_op.drop_column('body_html')
        batch_op.drop_column('language')
    with op.batch_alter_table('comment', schema=None) as batch_op:
        batch_op.drop_index(batch_op.f('ix_comment_timestamp'))
    op.drop_table('comment')
    with op.batch_alter_table('notification', schema=None) as batch_op:
        batch_op.drop_index(batch_op.f('ix_notification_timestamp'))
        batch_op.drop_index(batch_op.f('ix_notification_name'))
    op.drop_table('notification')
    with op.batch_alter_table('message', schema=None) as batch_op:
        batch_op.drop_index(batch_op.f('ix_message_timestamp'))
    op.drop_table('message')
    # ### end Alembic commands ###

Also, I checked history:

(venv) 12:28 ~/microblog (main)$ flask db history
9d026987d6f2 -> e6990a7ae19f (head), empty message
ceca8f22389c -> 9d026987d6f2, empty message
b07ebb5fe6e0 -> ceca8f22389c, user tokens
05eba44a406a -> b07ebb5fe6e0, fix markdown rendering of comments
fd8a7d4f9bd4 -> 05eba44a406a, notifications
9389414e987c -> fd8a7d4f9bd4, private messages
14ba2865cec3 -> 9389414e987c, enable markdown editor
f3cff53a2dcf -> 14ba2865cec3, add comments
e949960c17e9 -> f3cff53a2dcf, add language to posts
dc96d9b0d0bf -> e949960c17e9, let user be able to follow and unfollow
92a7096214ea -> dc96d9b0d0bf, followers
6ee987d26551 -> 92a7096214ea, new fields in user model
3d95c0a8c088 -> 6ee987d26551, posts table
<base> -> 3d95c0a8c088, users table

[CaselIT]

Hi,

I'm not sure if there is a question there. I don't know what you are trying to do, but generally you would not run stamp to change the revision, but you would run upgrade.

If you have an existing application running locally maybe you can take the db file (since you are using sqlite) and use that in the hosting?

[JTP-123]

Running upgrade does not work and error message reports:"The table is already exists". Indeed, I have local application which runs smoothly and works fine.

[JTP-123]

I runned flask db heads and found the head version e6990a7ae19f was different from the current version dc96d9b0d0bf which was about followers, it seems that stamp could fix this inconsistency

[JTP-123]

You mean I can replace the current database file app.db with my local one app.db?

[JTP-123]

I tried again and still met the same error The table user already exists, Can I delete the whole migrations directory?

[CaselIT]

You would need to check what the migration contain. You seems to have something wrong going on in the migration folder

[JTP-123]

I deleted migrations file and started from stratch using flask db init , then I runned command flask db migrate :

(env) 01:16 ~/microblog (main)$ flask db migrate
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.autogenerate.compare] Detected added table 'message'
INFO  [alembic.autogenerate.compare] Detected added index 'ix_message_timestamp' on '['timestamp']'
INFO  [alembic.autogenerate.compare] Detected added table 'notification'
INFO  [alembic.autogenerate.compare] Detected added index 'ix_notification_name' on '['name']'
INFO  [alembic.autogenerate.compare] Detected added index 'ix_notification_timestamp' on '['timestamp']'
INFO  [alembic.autogenerate.compare] Detected added table 'comment'
INFO  [alembic.autogenerate.compare] Detected added index 'ix_comment_timestamp' on '['timestamp']'
INFO  [alembic.autogenerate.compare] Detected added column 'post.language'
INFO  [alembic.autogenerate.compare] Detected added column 'post.body_html'
INFO  [alembic.autogenerate.compare] Detected type change from VARCHAR(length=140) to Text() on 'post.body'
INFO  [alembic.autogenerate.compare] Detected added column 'user.token'
INFO  [alembic.autogenerate.compare] Detected added column 'user.token_expiration'
INFO  [alembic.autogenerate.compare] Detected added column 'user.last_message_read_time'
INFO  [alembic.autogenerate.compare] Detected added index 'ix_user_token' on '['token']'
  Generating /home/JTPing/microblog/migrations/versions/786861124dfd_.py ...  done
(env) 01:16 ~/microblog (main)$ flask db upgrade

Finally, flask db upgrade was used:

(env) 01:16 ~/microblog (main)$ flask db upgrade
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade dc96d9b0d0bf -> 786861124dfd, empty message

But, still, I met same problem.