Fetch table values using alembic and update to another table.

Question

I have oauth secret and oauth key in client table. Now I moving them to oauth credentials table which will be created during

Answer 1

You can create a DBSession with sqlalchemy engine bind, then you can avoid use SQL query.

from myapp.models import Client, ClientCredential
from alembic import op, context
import sqlalchemy as sa


def upgrade():
    ### commands auto generated by Alembic - please adjust! ###
    url = context.config.get_main_option("sqlalchemy.url")
    engine = sa.create_engine(url)
    DBSession.configure(bind=engine)

    op.create_table(
        'client_credential',
        sa.Column('id', sa.Integer(), nullable=False),
        sa.Column('created_at', sa.DateTime(), nullable=False),
        sa.Column('updated_at', sa.DateTime(), nullable=False),
        sa.Column('client_id', sa.Integer(), nullable=False),
        sa.Column('key', sa.String(length=22), nullable=False),
        sa.Column('secret', sa.String(length=44), nullable=False),
        sa.Column('is_active', sa.Boolean(), nullable=False),
        sa.ForeignKeyConstraint(['client_id'], ['client.id'], ),
        sa.PrimaryKeyConstraint('id'),
        sa.UniqueConstraint('key'))
    # Here I need to copy data from table A to newly created Table.
    # Now Client table will not have secret and key attributes
    clients = [
        {'secret': client.secret,
         'key': client.key,
         'is_active': True,
         'client_id': client.id,
         'created_at': sa.func.now(),
         'updated_at': sa.func.now()}
        for client in Client.query.all()]
    op.bulk_insert(ClientCredential, clients)
    #Also replaced above two lines with
    #connection = op.get_bind()
    #print connection.execute(Client, Client.query.all())
    op.drop_column(u'client', u'secret')
    op.drop_column(u'client', u'key')