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Replace manual if-sqlite/if-postgres branching with Alembic: - Add alembic dependency - Create programmatic alembic env (no CLI/alembic.ini needed) - Support async engines via run_sync passthrough - render_as_batch=True for SQLite ALTER TABLE compatibility - Auto-stamp baseline on first run (existing DB at version 25) - Run alembic upgrade head after legacy migrations - Include sample migration showing schema + data migration patterns - Add alembic dir to package-data for distribution
63 lines
1.9 KiB
Python
63 lines
1.9 KiB
Python
"""example: sample migration demonstrating Alembic patterns
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This is a SAMPLE showing how to write migrations that work
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seamlessly across SQLite and PostgreSQL. Delete or adapt as needed.
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Revision ID: 0002_sample
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Revises: 0001_baseline
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Create Date: 2026-04-08
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Patterns demonstrated:
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1. Schema change (add column) — works on both DBs via render_as_batch
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2. Data migration (read + modify JSON) — pure SQLAlchemy, no dialect branching
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"""
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revision = '0002_sample'
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down_revision = '0001_baseline'
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branch_labels = None
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depends_on = None
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def upgrade() -> None:
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"""
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EXAMPLE: Uncomment to use. This shows the patterns.
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# --- Pattern 1: Schema change (add/drop column) ---
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# render_as_batch=True in env.py makes this work on SQLite too.
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#
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# op.add_column('pipelines', sa.Column('description', sa.String(512), server_default=''))
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# --- Pattern 2: Data migration (read + modify JSON field) ---
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# No if/else for sqlite vs postgres needed!
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#
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# conn = op.get_bind()
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# rows = conn.execute(sa.text("SELECT uuid, config FROM pipelines")).fetchall()
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# for row in rows:
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# config = json.loads(row[1]) if isinstance(row[1], str) else row[1]
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# # Modify the config
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# config.setdefault('ai', {}).setdefault('some_new_key', 'default_value')
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# conn.execute(
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# sa.text("UPDATE pipelines SET config = :cfg WHERE uuid = :uuid"),
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# {"cfg": json.dumps(config), "uuid": row[0]}
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# )
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# --- Pattern 3: Create a new table ---
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#
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# op.create_table(
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# 'audit_log',
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# sa.Column('id', sa.Integer, primary_key=True, autoincrement=True),
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# sa.Column('action', sa.String(255), nullable=False),
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# sa.Column('detail', sa.Text),
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# sa.Column('created_at', sa.DateTime, server_default=sa.func.now()),
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# )
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"""
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pass
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def downgrade() -> None:
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"""
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# op.drop_column('pipelines', 'description')
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# op.drop_table('audit_log')
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"""
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pass
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