更改唯一索引以在 postgresql 中将其设置为可延迟

Alter a unique index to set it deferrable in postgresq

我需要更改已创建的唯一索引以将其设置为可延迟。在 postgres 9.6 中。基本上,我会做类似的事情:

DROP TABLE IF EXISTS test;

CREATE TABLE test (id integer);

ALTER TABLE test ADD CONSTRAINT unique_id unique(id);

ALTER TABLE test ALTER CONSTRAINT unique_id DEFERRABLE INITIALLY DEFERRED;

但是我明白了

ERROR:  constraint "unique_id" of relation "test" is not a foreign key constraint

文档似乎没有提到无法执行此类操作。我错过了什么?

the documentation:

ALTER CONSTRAINT

This form alters the attributes of a constraint that was previously created. Currently only foreign key constraints may be altered.

相反,您可以:

ALTER TABLE test DROP CONSTRAINT unique_id;
ALTER TABLE test ADD CONSTRAINT unique_id unique(id) DEFERRABLE INITIALLY DEFERRED;