def produce_migrations(self):
"""Generate the :class:`~alembic.autogenerate.MigrationScript`
object that would generate a new revision.
"""
db = current_app.extensions["sqlalchemy"].db
return autogenerate.produce_migrations(self.migration_context,
db.metadata)
def upgrade():
'''
First migration.
Generates a migration script by difference between model and database and executes it
'''
target_metadata = Base.metadata
mc = context.get_context()
migration_script = produce_migrations(mc, target_metadata)
autogen_context = api.AutogenContext(
mc, autogenerate=True
)
# Seems to be the only way to apply changes to the database
template_args = {}
render._render_python_into_templatevars(
autogen_context, migration_script, template_args
)
code = template_args['upgrades']
code = code.replace('\n ', '\n')
print('\nPerforming database changes:')
print(code)
exec(code)
def test_alembic_autogenerate_nextbigid(Foo, connection, Base, engine):
from sqlalchemy_bigid import migration # noqa
context = MigrationContext.configure(
connection=connection,
)
migration_script = produce_migrations(context, Base.metadata)
first_upgrade_op = migration_script.upgrade_ops.ops[0]
assert isinstance(first_upgrade_op, CreateNextBigIdFunctionOp)
def generate_migration(metadata, engine):
"""Create MigrationContext and MigrationScript"""
mc = MigrationContext.configure(engine.connect())
ms = produce_migrations(mc, metadata)
ac = AutogenContext(None,
opts={
'sqlalchemy_module_prefix': 'sa.',
'alembic_module_prefix': 'op.',
})
lines = []
for x in ms.upgrade_ops.ops:
lines.append(render_op_text(ac, x))
return mc, lines
def migrate():
from alembic.runtime.migration import MigrationContext
# use `db.session.connection()` instead of `db.engine.connect()`
# to avoid lock hang
context = MigrationContext.configure(
db.session.connection(),
opts={
"compare_type": True,
},
)
if request.method == "GET":
import pprint
from alembic.autogenerate import compare_metadata
diff = compare_metadata(context, db.metadata)
diff_str = pprint.pformat(diff, indent=2, width=20)
logger.info("Migrate steps: %s", diff_str)
return respond_success(migration=diff_str)
from alembic.autogenerate import produce_migrations
from alembic.operations import Operations
from alembic.operations.ops import OpContainer
migration = produce_migrations(context, db.metadata)
operation = Operations(context)
for outer_op in migration.upgrade_ops.ops:
logger.info("Invoking %s", outer_op)
if isinstance(outer_op, OpContainer):
for inner_op in outer_op.ops:
logger.info("Invoking %s", inner_op)
operation.invoke(inner_op)
else:
operation.invoke(outer_op)
db.session.commit()
db.session.close()
return respond_success()
id integer not null primary key,
old_data varchar,
x integer
)""")
engine.execute('''
create table bar (
data varchar
)''')
metadata = MetaData()
Table('foo', metadata, Column('id', Integer, primary_key=True),
Column('data', Integer), Column('x', Integer, nullable=False))
Table('bat', metadata, Column('info', String))
ctx = MigrationContext.configure(engine.connect())
mc = produce_migrations(ctx, metadata)
ops = Operations(ctx)
op = mc.upgrade_ops.ops[0]
if __name__ == '__main__':
print(op)
print(ops.invoke(op))
# diff = compare_metadata(mc, metadata)
# pprint.pprint(diff, indent=2, width=20)
def get_outstanding_migrations(self):
return produce_migrations(
MigrationContext.configure(connection=Session.connection()),
metadata)