水线将现有数据库迁移到没有帆的水线模型

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。我不使用帆。只是水线独立。我已将连接设置为安全迁移。但是，水线仍在尝试创建一个已经存在于我预先存在的数据库中的表。如果我将 tableName 设为一个新名称，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。

我认为这是一个错误，因为 migrate safe 根本不应该尝试创建表吗？

我正在使用没有帆的水线。

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
    }
``` 

顺便说一下，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。我试过这样做，但也许我错过了一些小东西。它在水线代码中的哪个位置检查模型 == 模式定义？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。数十亿公司的主要生产级别错误:(

提前致谢

更多信息：表的 sql 看起来像这样

```
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;
```

还有我的模特：

```
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

迁移功能需要在每个模型上而不是在连接上。根据这个线程：https://github.com/balderdashy/waterline/issues/1472