On Tue, Aug 27, 2019, at 6:15 AM, Mike wrote:
> *Setup:*
> mysql> SELECT version();
>
> * 5.7.27-0ubuntu0.18.04.1
> * Python 3.6.8
> * SQLAlchemy 1.3.6
> * Alembic 1.0.11
>
>
> *models.py:*
> class Experiments(db.Model):
> id = db.Column(db.Integer, primary_key=True)
> # country = db.Column(db.String(100))
> countryland = db.Column(db.String(100))
>
> insert_date = db.Column(db.DateTime, index=True,
> default=datetime.utcnow)
>
>
> *SQL data:*
> INSERT INTO experiments (country)
> VALUES ('US'),
> ('Canada'),
> ('Mexico'),
> ('Brazil'),
> ('Argentina'),
> ('Spain'),
> ('Portugal'),
> ('France'),
> ('Germany'),
> ('UK');
>
>
> *migration file:*
> def upgrade():
> # ### commands auto generated by Alembic - please adjust! ###
>
> # op.add_column('experiments', sa.Column('countryland',
> sa.String(length=100), nullable=True))
> # op.drop_column('experiments', 'country')
>
> op.alter_column('experiments', column_name='country',
> new_column_name='countryland')
hi there -
for MySQL the alter_column() operation requires that you pass the existing
information about the column as well:
op.alter_column('table", column_name='a', new_column_name='b',
existing_type=String, existing_nullable=False, existing_server_default=...)
see
https://alembic.sqlalchemy.org/en/latest/ops.html?highlight=alter_column#alembic.operations.Operations.alter_column
for the full list of parameters.
>
> # ### end Alembic commands ###
>
>
>
> *Problem:*
> I want to rename the column name from *"country"* to *"countryland"*. But I'm
> getting this error in my terminal can anybody help me please?
>
> $ flask db upgrade
>
> [2019-08-27 11:43:26,155] INFO in __init__: microblog startup
> INFO [alembic.runtime.migration] Context impl MySQLImpl.
> INFO [alembic.runtime.migration] Will assume non-transactional DDL.
> INFO [alembic.runtime.migration] Running upgrade 1f866a4fa5a0 ->
> 69e7cfcf87f1, Testing column rename 02.
> ERROR [root] Error: All MySQL CHANGE/MODIFY COLUMN operations require the
> existing type.
>
>
> Electronically yours,
> Mike
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "sqlalchemy-alembic" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/sqlalchemy-alembic/0e9b482c-0f31-4492-b1b8-df97bc84adbd%40googlegroups.com
>
> <https://groups.google.com/d/msgid/sqlalchemy-alembic/0e9b482c-0f31-4492-b1b8-df97bc84adbd%40googlegroups.com?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy-alembic" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/sqlalchemy-alembic/72aeffce-ffa7-4fed-83ef-d7a0e92d6f1f%40www.fastmail.com.
