40 lines
1.3 KiB
Python
40 lines
1.3 KiB
Python
"""领取用的分段 UPDATE。
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每段 500 个 fid，避开 Oracle 一条 IN 最多 1000 个表达式。
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调用方持有事务：本模块不提交。任一段失败由调用方整笔回滚。
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"""
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from __future__ import annotations
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FID_CHUNK_SIZE = 500
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def update_by_fid_chunks(
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cur,
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sql_template: str,
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fids: list[int],
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binds: dict | None = None,
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) -> None:
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"""按每段 500 个 fid 执行同一条 UPDATE。
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sql_template 用 {placeholders} 放本段占位符。各段在当前游标上顺序执行，不提交。
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空列表不执行。任一段抛错时前面各段已执行但未提交，调用方应整笔回滚。
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"""
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if not fids:
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return
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extra = dict(binds or {})
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for start in range(0, len(fids), FID_CHUNK_SIZE):
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chunk = list(fids[start : start + FID_CHUNK_SIZE])
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placeholders, fid_binds = _fid_placeholders(chunk)
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cur.execute(
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sql_template.format(placeholders=placeholders),
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{**extra, **fid_binds},
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)
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def _fid_placeholders(fids: list[int]) -> tuple[str, dict[str, int]]:
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"""把本段 fid 编成 :id0, :id1 占位和 bind。段内从 0 编号。"""
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fid_binds = {f"id{index}": value for index, value in enumerate(fids)}
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placeholders = ", ".join(f":id{index}" for index in range(len(fids)))
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return placeholders, fid_binds
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