flask - python manage.py db upgrade 语句不起作用

Question

最近在学Flask，书籍是《Flask.Web.Development》，其中数据库迁移工具使用的是Flask-Migrate，书中提到创建迁移脚本后更新数据库使用python manage.py db upgrade就可以更新数据库，但是我在使用过程中模型修改...

PHP中文网 · Answer

Database migration is generally divided into two steps

Generate migration script
Run the script and change the database

Before upgrade you need migrate

After modifying model
Need to python manage.py db migrate
first Then python manage.py db upgrade

阿神 · Answer

The problem I encountered was after changing the existing field type migration. There are no changes in the migration script. Solve. . . .

# revision identifiers, used by Alembic.
revision = '5588e49798f0'
down_revision = '53ffda24441'

from alembic import op
import sqlalchemy as sa


def upgrade():
    ### commands auto generated by Alembic - please adjust! ###
    pass
    ### end Alembic commands ###


def downgrade():
    ### commands auto generated by Alembic - please adjust! ###
    pass
    ### end Alembic commands ###

伊谢尔伦 · Answer

The title’s question seems to have gone beyond the scope of the original book.

The first time you enter python hello.py db upgrade is equivalent to db.creat_all(), and the next time you enter python hello.py db upgrade is to update the database. The questioner has already taken the first step, and now his attempt to update fails.

So the problem should occur in the step of updating the database. Post how you subsequently modified the database to continue analyzing the problem.
I am also currently studying, so I don’t know if this understanding is correct.