node.js - Waterline 将现有数据库迁移到无 sails 的水线模型

Question

 Error (E_UNKNOWN) :: Encountered an unexpected error
: Trying to define a collection (external_resource) which already exists.

我正在尝试为现有数据库创建模型。我没有使用 sails 。只是水线独立。我已将连接设置为安全迁移。然而，waterline 仍在尝试创建一个已存在于我预先存在的数据库中的表。如果我为 tableName 指定一个新名称，它就可以正常工作。问题似乎是当我尝试使用现有表中的现有数据，然后为其创建水线模型时。

我相信这是一个错误，因为迁移安全根本不应该尝试创建表，对吗？

我使用的是没有 sails 的水线。

水线配置如下:

```
models = [];
fs.readdirSync(HOMEDIR + '/lib/models/waterline').forEach(function(file) {
  models.push(require(HOMEDIR + '/lib/models/waterline/' + file));
});

module.exports = {
  init: function(next) {
    models.forEach(function(model) {
      orm.loadCollection(model);
    });

    orm.initialize(config, function(err, models) {
      if (err) throw err;
      global.models = models.collections;
      global.connections = models.connections;
      next();
    });
  }
};


//And this in my config
localhost: {
      migrate: 'safe',
      adapter: 'postgres',
      database: 'intellinote',
      host: 'localhost',
      user: 'postgres',
      password: '',
      port: 5432
    }
``` 

顺便使用 sails-postgresql。 "sails-postgresql": "^0.11.4",

我的一个假设是我的模型定义与我的 postgresql 模型不完全匹配。我尝试过这样做，但也许我错过了一些小事情。它在水线代码中的哪个位置检查 model == schema 定义？也许如果我知道这一点，我就能找到为什么要尝试创建

Sails 用户 3 年。值(value)数十亿美元的公司的主要生产级别错误:(

提前致谢

更多信息:表的 SQL 如下所示

```
DROP TABLE IF EXISTS "intellinotedb"."external_resource";
CREATE TABLE "intellinotedb"."external_resource" (
    "id" int8 NOT NULL DEFAULT nextval('external_resource_id_seq'::regclass),
    "external_id" varchar(2000) NOT NULL COLLATE "default",
    "version_id" varchar(2000) COLLATE "default",
    "url" varchar(5000) COLLATE "default",
    "name" varchar(4000) COLLATE "default",
    "size" int8,
    "creator" varchar(50) NOT NULL COLLATE "default",
    "created_at" timestamp(6) NOT NULL DEFAULT now(),
    "modified_at" timestamp(6) NULL,
    "project_id" int8 NOT NULL,
    "note_id" int8,
    "type" varchar(50) NOT NULL COLLATE "default",
    "is_public" bool NOT NULL DEFAULT false,
    "state" varchar(100) NOT NULL DEFAULT 'ACTIVE'::character varying COLLATE "default",
    "mime_type" text COLLATE "default",
    "internal_type" text COLLATE "default",
    "is_template" bool NOT NULL,
    "has_filled_data" bool NOT NULL
)
WITH (OIDS=FALSE);
ALTER TABLE "intellinotedb"."external_resource" OWNER TO "intellinote";

-- ----------------------------
--  Primary key structure for table external_resource
-- ----------------------------
ALTER TABLE "intellinotedb"."external_resource" ADD PRIMARY KEY ("id") NOT DEFERRABLE INITIALLY IMMEDIATE;

-- ----------------------------
--  Uniques structure for table external_resource
-- ----------------------------
ALTER TABLE "intellinotedb"."external_resource" ADD CONSTRAINT "external_resource_note_id_key" UNIQUE ("note_id") NOT DEFERRABLE INITIALLY IMMEDIATE;

-- ----------------------------
--  Foreign keys structure for table external_resource
-- ----------------------------
ALTER TABLE "intellinotedb"."external_resource" ADD CONSTRAINT "external_resource_note_id_fkey" FOREIGN KEY ("note_id") REFERENCES "intellinotedb"."note" ("id") ON UPDATE NO ACTION ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE;
ALTER TABLE "intellinotedb"."external_resource" ADD CONSTRAINT "external_resource_project_id_fkey" FOREIGN KEY ("project_id") REFERENCES "intellinotedb"."project" ("id") ON UPDATE NO ACTION ON DELETE NO ACTION NOT DEFERRABLE INITIALLY IMMEDIATE;
```

还有我的模型:

```
Waterline = require('waterline');

module.exports = Waterline.Collection.extend({
  tableName: 'external_resource',
  meta: {
    schemaName: process.env.WATERLINE_SCHEMA || 'intellinotedb'
  },
  connection: process.env.WATERLINE_DB || 'localhost',
  attributes: {
    id: {
      type: 'integer',
      autoIncrement: true,
      primaryKey: true,
      unique: true,
      size: 8
    },
    external_id: {
      type: 'string',
      required: true,
      size: 2000
    },
    version_id: {
      type: 'string',
      size: 2000
    },
    url: {
      type: 'string',
      required: true,
      size: 5000
    },
    name: {
      type: 'string',
      required: true,
      size: 4000
    },
    size: {
      type: 'integer',
      required: true,
      size: 8
    },
    creator: {
      type: 'string',
      required: true,
      size: 50
    },
    createdAt: {
      type: 'datetime',
      columnName: 'created_at'
    },
    updatedAt: {
      type: 'datetime',
      columnName: 'modified_at'
    },
    project_id: {
      type: 'integer',
      required: true
    },
    note_id: {
      type: 'integer',
      required: true,
      size: 8
    },
    type: {
      type: 'string',
      defaultsTo: 'FILE',
      required: true,
      size: 50
    },
    is_public: {
      type: 'boolean',
      defaultsTo: true,
      required: true
    },
    state: {
      type: 'string',
      enum: ['ACTIVE', 'DELETED'],
      defaultsTo: 'ACTIVE',
      required: true,
      size: 100
    },
    mime_type: {
      type: 'string',
      required: true
    },
    internal_type: {
      type: 'string',
      defaultsTo: 'REGULAR',
      required: true
    },
    is_template: {
      type: 'boolean',
      defaultsTo: false,
      required: false
    },
    has_filled_data: {
      type: 'boolean',
      defaultsTo: false,
      required: false
    }
  }
});

```

Answer 1

迁移功能需要位于每个模型上，而不是连接上。根据此线程:https://github.com/balderdashy/waterline/issues/1472