Haskell 持久不同步 [英] Haskell Persistent out of sync

问题描述

我正在使用 Yesod 和 Persistent 制作博客(真的很原创，嗯?).

I'm using Yesod and Persistent to make a blog (really original, eh?).

在某个时候，我改变了我的模型，Persistent 说我尝试做的事情不安全，我必须手动完成.它说:

At some point, I changed my model, and Persistent said that what I was trying to do is unsafe, and that I would have to do it manually. It said:

Database migration: manual intervention required.
The following actions are considered unsafe:

    ALTER TABLE "article" DROP COLUMN "date";

所以我继续在 Postgres 中运行它.事实上，我已经继续删除表文章"，我得到了错误:

So I went ahead and ran that in Postgres. In fact, I have gone ahead and dropped the table "article", and I get the error:

Migrating: CREATe TABLE "article" 
      ( "id" SERIAL PRIMARY KEY UNIQUE,
        "title" VARCHAR NOT NULL,
        "author" VARCHAR NOT NULL,
        "day" DATE NOT NULL DEFAULT DATE,
        "content" VARCHAR NOT NULL)

devel.hs: SqlError { sqlState = "42703"
                   , sqlExecStatus = FatalError
                   , sqlErrorMsg = "column \"date\" does not exist"
                   , sqlErrorDetail = ""
                   , sqlErrorHint = ""
                   }

以下是架构当前的外观(使用 Persistent 定义):

Here is how the schema currently looks (as defined using Persistent):

-- Blog Article
Article
  title   Text
  author  Text
  day     Day default=DATE
  content MathJax 

这里发生了什么?我该怎么做才能让 Postgres 和 Persistent 重新同步?

What is going on here? What do I have to do to get Postgres and Persistent back in sync?

推荐答案

请将您的创建表代码更改为:

please change your create table code to :

    digoal=# CREATE TABLE "article" 
      ( "id" SERIAL PRIMARY KEY UNIQUE,
        "title" VARCHAR NOT NULL,
        "author" VARCHAR NOT NULL,
        "day" DATE NOT NULL DEFAULT current_date,
        "content" VARCHAR NOT NULL);
    CREATE TABLE

PostgreSQL 没有 DATA 函数，所以你可以用 current_date 代替.

PostgreSQL no DATA function, so you can use current_date instead.

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