我无法在 Loopback ORM 模型中设置唯一字段

Question

我是 Loopback 3 的新手。 我需要用唯一字段定义模型。 电子邮件字段应该是唯一的。我使用 Postgresql 作为数据库。

我尝试添加 "unique": true 选项。此外，我尝试遵循以下建议：Ensure unique field value in loopback model。但它没有给出预期的结果。

 "properties": {
    "id": {
      "type": "number",
      "id": true,
      "generated": true,
      "postgresql": {
        "dataType": "bigint"
      }
    },
    "name": {
      "type": "string",
      "postgresql": {
        "dataType": "character varying"
      }
    },
    "email": {
      "type": "varchar",
      "postgresql": {
        "dataType": "character varying"
      }
    },
    "added_date": {
      "type": "date",
      "postgresql": {
        "dataType": "date"
      }
    }
  }

最终，我希望在 Postgres 方案中有一个独特的字段。 在 Postgres 中应该是这样的：

-- Table: public."user"

-- DROP TABLE public."user";

CREATE TABLE public."user"
(
    id bigint NOT NULL DEFAULT nextval('user_id_seq'::regclass),
    name character varying COLLATE pg_catalog."default",
    email character varying COLLATE pg_catalog."default",
    added_date date,
    CONSTRAINT user_pkey PRIMARY KEY (id),
    CONSTRAINT user_email_key UNIQUE (email)

)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE public."user"
    OWNER to postgres;

Answer 1

我认为这些会起作用。将index 属性添加到列def，或者将其添加到模型的索引部分。奇怪的是没有更多的文档。

 "properties": {
    "id": {
      "type": "number",
      "id": true,
      "generated": true,
      "postgresql": {
        "dataType": "bigint"
      }
    },
    "name": {
      "type": "string",
      "postgresql": {
        "dataType": "character varying"
      }
    },
    "email": {
      "type": "varchar",
      "postgresql": {
        "dataType": "character varying"
      }
    },
    "added_date": {
      "type": "date",
      "postgresql": {
        "dataType": "date"
      }
    }
  },
  "indexes": {
    "EMAIL_INDEX": {
      "columns": "email",
      "kind": "unique"
    }
  }

或者

 "properties": {
    "id": {
      "type": "number",
      "id": true,
      "generated": true,
      "postgresql": {
        "dataType": "bigint"
      }
    },
    "name": {
      "type": "string",
      "postgresql": {
        "dataType": "character varying"
      }
    },
    "email": {
      "type": "varchar",
      "postgresql": {
        "dataType": "character varying"
      },
      "index": {"kind": "UNIQUE"}
    },
    "added_date": {
      "type": "date",
      "postgresql": {
        "dataType": "date"
      }
    }
  }