PostgreSQL ON CONFLICT DO UPDATE with not null column and COALESCE EXCLUDED column

Question

我想对可能包含 not null 约束违规但不引发错误的数据执行 UPSERT。我希望跳过建议的行而不是错误。

架构：

               Table "public.appointments"
    Column   |            Type             |  Modifiers
-------------+-----------------------------+--------------
 id          | bigint                      | not null
 location_id | bigint                      | not null
 time        | timestamp without time zone | not null
 status      | text                        | not null
Indexes:
    "appointments_pkey" PRIMARY KEY, btree (id)
    "for_upsert" UNIQUE CONSTRAINT, btree (id, location_id)

现有记录：

 id | location_id | status |       time         
----+-------------+--------+----------------------
  1 |           2 | sched  | 2017-12-15 01:10:00
  2 |           2 | sched  | 2017-12-19 01:30:00

查询：

INSERT INTO "objects" ("id", "location_id", "time")
  VALUES (1, 2, 'sched', '2017-10-31 19:25:00'),
         (2, 2, 'canc', NULL),
         (3, 2, 'canc', NULL)
  ON CONFLICT ON CONSTRAINT for_upsert DO UPDATE
    SET "time" = COALESCE(EXCLUDED."time", "objects"."time"),
        "status" = EXCLUDED."status"

当存在 time 不为空的记录时，我希望更新 status 而不管 EXCLUDED."time" 值（这就是 COALESCE 试图做的）。但是，如果没有现有记录并且新提议的行具有空 time 我不希望插入该行或引发错误。

Answer 1

添加此子句：

    WHERE COALESCE(EXCLUDED."time", "appointments"."time") IS NOT NULL;

在 DO UPDATE SET... 似乎工作之后。

PostgreSQL ON CONFLICT DO UPDATE with not null column and COALESCE EXCLUDED column

PostgreSQL ON CONFLICT DO UPDATE with not null column and COALESCE EXCLUDED column

postgresql

constraints

upsert