45 lines
1.2 KiB
Python
45 lines
1.2 KiB
Python
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"""Add content_hash column to files table for SHA-256 dedup and integrity.
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Revision ID: 0038_dms_content_hash
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Revises: 0037_user_tenant_model
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Create Date: 2026-07-25
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Changes:
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1. Add content_hash (String(64), nullable) column to files table.
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"""
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from __future__ import annotations
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from typing import Union
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import sqlalchemy as sa
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from alembic import op
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# revision identifiers
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revision: str = "0038_dms_content_hash"
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down_revision: Union[str, None] = "0037_user_tenant_model"
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branch_labels: Union[str, None] = None
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depends_on: Union[str, None] = None
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def _column_exists(table: str, column: str) -> str:
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"""Return SQL that checks if a column exists on a table."""
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return (
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f"SELECT 1 FROM information_schema.columns "
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f"WHERE table_name = '{table}' AND column_name = '{column}'"
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)
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def upgrade() -> None:
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conn = op.get_bind()
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result = conn.execute(sa.text(_column_exists("files", "content_hash"))).fetchone()
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if result is None:
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op.add_column("files", sa.Column("content_hash", sa.String(64), nullable=True))
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def downgrade() -> None:
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conn = op.get_bind()
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result = conn.execute(sa.text(_column_exists("files", "content_hash"))).fetchone()
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if result is not None:
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op.drop_column("files", "content_hash")
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