如何在冲突时更新 select 的确切行？

Question

我只需要在冲突时更新，并且所有选中的行

INSERT INTO t  SELECT * FROM fdw_t
  ON CONFLICT (id) DO UPDATE
     SET  id=id, etc1=etc1, etc2=etc2
; -- ERROR: column reference "id" is ambiguous

INSERT INTO t  SELECT * FROM fdw_t AS w
  ON CONFLICT (id) DO UPDATE
     SET  id=w.id, etc1=w.etc1, etc2=etc2
; -- ERROR: missing FROM-clause entry for table "w"
  -- BUT I NEED the ROW of the select, not other!

Answer 1

您可以像使用 VALUES 子句执行 INSERT 时那样引用 EXCLUDED 行：

INSERT INTO t
SELECT * FROM fdw_t
ON CONFLICT (id)
DO UPDATE
SET id = EXCLUDED.id, etc1 = EXCLUDED.etc1, etc2 = EXCLUDED.etc2;

如何在冲突时更新 select 的确切行？

How update the exact row of the select, on conflict?

postgresql

upsert