Question

我正在研究Author hasmany Books示例，并尝试运行sequelize-cli迁移，但是在运行以下迁移时遇到以下问题：

ERROR: relation "authors" does not exist

这是第一个创建作者的迁移：

'use strict';
module.exports = {
  up: (queryInterface, Sequelize) => {
    return queryInterface.createTable('Authors', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      firstName: {
        type: Sequelize.STRING
      },
      lastName: {
        type: Sequelize.STRING
      },
      dateOfBirth: {
        type: Sequelize.DATEONLY
      },
      dateOfDeath: {
        type: Sequelize.DATEONLY
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  down: (queryInterface, Sequelize) => {
    return queryInterface.dropTable('Authors');
  }
};

第二个创建书的迁移：

'use strict';
module.exports = {
  up: (queryInterface, Sequelize) => {
    return queryInterface.createTable('Books', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      title: {
        type: Sequelize.STRING
      },
      summary: {
        type: Sequelize.STRING
      },
      isbn: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  down: (queryInterface, Sequelize) => {
    return queryInterface.dropTable('Books');
  }
};

创建作者和作者之间关系的迁移本书：

'use strict';

module.exports = {
  up: (queryInterface, Sequelize) => {
    return queryInterface.addColumn(
      'Books', // name of source model
      'AuthorId',
      {
        type: Sequelize.INTEGER,
        references: {
          model: 'authors',
          key: 'id'
        },
        onUpdate: 'CASCADE',
        onDelete: 'SET NULL'
      }
    )
  },

  down: (queryInterface, Sequelize) => {
    return queryInterface.removeColumn(
      'Books',
      'AuthorId'
    )
  }
};

这些是我的模型：

author.js：

'use strict';
module.exports = (sequelize, DataTypes) => {
  var Author = sequelize.define('Author', {
    firstName: { type: DataTypes.STRING, allowNull: false, len: [2, 100] },
    lastName: { type: DataTypes.STRING, allowNull: false },
    dateOfBirth: { type: DataTypes.DATEONLY },
    dateOfDeath: { type: DataTypes.DATEONLY }
  }, {});
  Author.associate = function (models) {
    // associations can be defined here
    Author.hasMany(models.Book);
  };
  return Author;
};

book.js：

'use strict';
module.exports = (sequelize, DataTypes) => {
  var Book = sequelize.define('Book', {
    title: { type: DataTypes.STRING, allowNull: false, len: [2, 100], trim: true },
    summary: { type: DataTypes.STRING, allowNull: false },
    isbn: { type: DataTypes.STRING, allowNull: false }
  }, {});

  Book.associate = function (models) {
    // associations can be defined here
    Book.belongsTo(models.Author);
  };
  return Book;
};

我尝试了各种尝试都无济于事。我的猜测是，它正在尝试以异步方式更改表，但是先前的迁移已运行并完成：

我正在使用以下代码：

"pg": "^7.4.3"
"sequelize": "^4.37.10"
"sequelize-cli": "^4.0.0"
 "express": "~4.16.0"

我是续集的新手，我们将不胜感激！

Answer 1

您已经创建了Authors表，但是用小的a引用了该表。应该是

references: {
  model: 'Authors',
  key: 'id'
},

Answer 2

我正面临类似的问题，所以我如何实现它-

复制该迁移文件中的代码并删除迁移文件。
然后，我生成了一个新的迁移文件，并粘贴了我先前复制并运行sequelize db:migrate的代码。

顺序迁移：不存在关系

2 个答案: