node.js - Sequelize 迁移脚本引发错误未处理的拒绝 SequelizeddataBaseError : SQLITE_ERROR: no such table

Question

我已经编写了sequelizer迁移javascript来对表中的现有列进行更改，但是当我运行命令sequelizer db:migrate ，它给出了错误

== 20170212050240-alter_col_tag_subject:迁移======= 未处理的拒绝 SequelizeBaseError:SQLITE_ERROR:没有这样的表:subject_tags == 20170212050240-alter_col_tag_subject:已迁移(0.241s)

这是迁移文件的代码

'use strict';

module.exports = {
    up: function (queryInterface, Sequelize) {
        return [
                queryInterface.changeColumn(
                  'subject_tags',
                  'tag',
                    {
                       type: Sequelize.STRING,
                       unique: true,
                        validate: {
                            len: [1, 250]
                        }
                    }
                ),
                queryInterface.changeColumn(
                  'subject_tags',
                  'tag_description',
                    {
                        type: Sequelize.STRING,
                        allowNull: false,
                        validate: {
                            len: [1, 250]
                        }
                    }
                ),
                queryInterface.changeColumn(
                  'subject_tags',
                  'associated_subject',
                    {
                        type: Sequelize.STRING,
                        allowNull: false,
                        validate: {
                            len: [1, 250]
                        }
                    }
                )
        ];
  },

  down: function (queryInterface, Sequelize) {

  }
};

有人知道我为什么会遇到这个问题吗？

Answer 1

经过大量谷歌搜索后，我在 github 中找到了答案 discussion

引用 sdepold

Hey guys. The migration functions are supposed to return promises. So if you want to do multiple things in a migration, just return a chained promised like this:

return queryInterface.removeColumn('users', 'email').then(function () {
  return queryInterface.removeColumn('users', 'encryptedPassword');
});

因此是正确的代码

module.exports = {
    up: function (queryInterface, Sequelize) {
        return queryInterface.changeColumn(
                  'subject_tags',
                  'tag',
                    {
                       type: Sequelize.STRING,
                       unique: true,
                        validate: {
                            len: [1, 250]
                        }
                    }
                ). then( function () {

                   return queryInterface.changeColumn(
                    #.......
                    );
                }).then( function () {
                    return queryInterface.changeColumn(
                    #.......
                    );
                }) ;

希望这能回答问题。