LEVEL 层次伪列在 postgresql 16 支持吗？

判定为 none。CONNECT BY LEVEL<=n 生成行改 generate_series

ORACLE LEVEL 层次伪列迁移 postgresql 16 怎么改

支持度none

严重度major

置信度high

依据规则ora.syntax.level_pseudocolumn

WITH RECURSIVE + depth 列

CONNECT BY LEVEL<=n 生成行改 generate_series

库侧改造

可行：对象内随 CONNECT BY 整体改 WITH RECURSIVE 的 depth 列

应用侧改造

可行：行生成用法（CONNECT BY LEVEL<=n）改 generate_series；层次用法随主查询改写

推荐路线：app_side。验证建议：层级值与行数比对；与 connect_by 规则联动改写，勿单独处理

SELECT ename, LEVEL FROM emp START WITH mgr IS NULL CONNECT BY PRIOR empno = mgr

SELECT LEVEL AS n FROM dual CONNECT BY LEVEL <= 10

SELECT t.level FROM risk_level t