51 lines
1.5 KiB
Python
51 lines
1.5 KiB
Python
"""标准时间字段：Unix 秒级时间戳、默认值与 updated_at 自动维护。
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业务表若包含 created_at / updated_at，在 CREATE TABLE 后调用
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``init_updated_at_trigger(cursor, table_name)``。模板默认不建业务表。
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"""
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from __future__ import annotations
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STANDARD_TIMESTAMP_COLUMNS = frozenset({"created_at", "updated_at"})
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DATETIME_UNIX_SECONDS = "datetime_unix_seconds"
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def updated_at_trigger_name(table_name: str) -> str:
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return f"{table_name}_set_updated_at"
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def _quote_identifier(name: str) -> str:
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return '"' + name.replace('"', '""') + '"'
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def init_updated_at_trigger(cursor, table_name: str) -> None:
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"""幂等创建 {table}_set_updated_at：业务字段 UPDATE 后刷新 updated_at。"""
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trigger = updated_at_trigger_name(table_name)
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quoted = _quote_identifier(table_name)
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quoted_trigger = _quote_identifier(trigger)
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cursor.execute(
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f"""
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CREATE TRIGGER IF NOT EXISTS {quoted_trigger}
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AFTER UPDATE ON {quoted}
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FOR EACH ROW
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BEGIN
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UPDATE {quoted}
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SET updated_at = unixepoch()
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WHERE id = NEW.id AND updated_at = OLD.updated_at;
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END
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"""
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)
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def has_updated_at_trigger(cursor, table_name: str) -> bool:
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trigger_name = updated_at_trigger_name(table_name)
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cursor.execute(
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"""
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SELECT 1 FROM sqlite_master
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WHERE type = 'trigger' AND name = ? AND tbl_name = ?
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LIMIT 1
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""",
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(trigger_name, table_name),
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)
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return cursor.fetchone() is not None
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