pingcap/tidb

Expression inside window should not support legacy position indication

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#10,521 建立於 2019年5月17日

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 (2 留言) (0 反應) (1 負責人)Go (40,090 star) (6,186 fork)batch import
help wantedpriority/P4type/compatibility

描述

Bug Report

Please answer these questions before submitting your issue. Thanks!

  1. What did you do? If possible, provide a recipe for reproducing the error.
CREATE TABLE t(i INT, j INT, k INT);
SELECT i/SUM(j) OVER (PARTITION BY kk) AS x FROM t;
  1. What did you expect to see?
ERROR HY000: Window '<unnamed window>': ORDER BY or PARTITION BY uses legacy position indication which is not supported, use expression.
  1. What did you see instead?
Unknown column 'i' in 'field list'
  1. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?

貢獻者指南

技術棧
gomysql
領域
backenddatabase
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
half day
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
Understanding of SQL window functionsFamiliarity with TiDB's SQL parser
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
20
研究方向
The bug is that an expression inside a window function incorrectly reports 'Unknown column' instead of 'legacy position indication not supported'. The fix requires modifying the SQL parser to detect legacy position indication (e.g., using integer literals) in window function's PARTITION BY or ORDER BY clauses and produce the correct error. Look at the window function parsing logic in the parser package, likely in files like `parser/ast.go` or `planner/core/planbuilder.go`. Check the existing error handling and the condition for legacy position indication. The maintainers may have feedback in the comments.