具有 2 个唯一约束的 Postgres upsert

Question

我有一个带有 2 个唯一索引的 table 以允许其中一列中的空值。

CREATE TABLE public.pairs_dup
(
    id integer NOT NULL GENERATED ALWAYS AS IDENTITY ( INCREMENT 1 START 1 MINVALUE 1 MAXVALUE 2147483647 CACHE 1 ),
    base integer NOT NULL,
    quote integer NOT NULL,
    delivery_date timestamp with time zone,
    data float,
    CONSTRAINT pairs_dup_pkey PRIMARY KEY (id)
)

CREATE UNIQUE INDEX pairs_dup_not_null_idx
    ON public.pairs_dup USING btree
    (base ASC NULLS LAST, quote ASC NULLS LAST, delivery_date ASC NULLS LAST)
    WHERE delivery_date IS NOT NULL;

CREATE UNIQUE INDEX pairs_dup_null_idx
    ON public.pairs_dup USING btree
    (base ASC NULLS LAST, quote ASC NULLS LAST)
    WHERE delivery_date IS NULL;

A) 我可以在提供 delivery_date 时执行更新插入吗？

INSERT INTO pairs_dup(base, quote, delivery_date, data) values ('A', 'B', '2016-06-22 19:10:25-07', 0.5)
ON CONFLICT (base, quote, delivery_date) DO UPDATE SET data = 0.5;

B) 我可以在不提供交货日期的情况下执行更新插入吗？

INSERT INTO pairs_dup(base, quote, data) values ('A', 'B', 0.5)
ON CONFLICT (base, quote, delivery_date) DO UPDATE SET data = 0.5;

Answer 1

Ad A): 是的，但是 ON CONFLICT 子句需要包含索引谓词：

INSERT INTO pairs_dup(base, quote, delivery_date, data)
   VALUES (42, 4711, '2016-06-22 19:10:25-07', 0.5)
ON CONFLICT (base, quote, delivery_date)
   WHERE delivery_date IS NOT NULL  /* this is essential */
   DO UPDATE SET data = 0.5;

正如the documentation所说：

<em><strong>index_predicate</strong></em>

Used to allow inference of partial unique indexes. Any indexes that satisfy the predicate (which need not actually be partial indexes) can be inferred.

广告 B)：同样，您必须将 WHERE delivery_date IS NULL 添加到 ON CONFLICT 子句。

添加这些子句似乎是多余的，但这是必需的，以便可以推断出部分索引。

具有 2 个唯一约束的 Postgres upsert

Postgres upsert with 2 unique constraints

postgresql

upsert

unique-index

sql-insert