续集-添加列并执行查询

Question

我是使用Sequelize的新手，并且正在尝试使用Migration。在 up（）中，我创建表 messages ，然后将某些信息从电子邮件复制到 messages 并从电子邮件中删除一些列。

up: (queryInterface, Sequelize) => {
    queryInterface.createTable('messages', {
            id: {
                allowNull: false,
                autoIncrement: false,
                primaryKey: true,
                type: Sequelize.STRING
            },
            email_id: {
                type: Sequelize.STRING
            },
            conversation_id: {
                type: Sequelize.STRING
            },
            sender_id: {
                type: Sequelize.STRING
            },
            recipient_id: {
                type: Sequelize.STRING
            },
            marked_as_read: {
                allowNull: true,
                type: Sequelize.DATE
            },
            sent_at: {
                allowNull: true,
                type: Sequelize.DATE
            },
            created_at: {
                allowNull: false,
                type: Sequelize.DATE
            },
            updated_at: {
                allowNull: false,
                type: Sequelize.DATE
            }
        })
        .then(() => {
            queryInterface.sequelize.query(
                'INSERT INTO messages (id, email_id, conversation_id, sender_id, recipient_id, created_at, updated_at) ' +
                'select message_id, id, conversation_id, sender_id, recipient_id, created_at, updated_at from emails'
            ).then(() => {
                queryInterface.removeColumn('emails', 'message_id');
                queryInterface.removeColumn('emails', 'sender_id');
                queryInterface.removeColumn('emails', 'recipient_id');
                return true;
            });
        })
},

这很好用。

在 down（）中，我再次创建列，再次复制信息，并删除 messages 表。

down: (queryInterface, Sequelize) => {
    queryInterface.addColumn('emails', 'sender_id', {
        type: Sequelize.STRING,
        after: "conversation_id",
        allowNull: true
    }).then(() => {
        queryInterface.addColumn('emails', 'recipient_id', {
            type: Sequelize.STRING,
            after: "conversation_id",
            allowNull: true
        }).then(() => {
            queryInterface.addColumn('emails', 'message_id', {
                type: Sequelize.STRING,
                after: "conversation_id",
                allowNull: true
            }).then(() => {
                queryInterface.sequelize.query(
                    'update emails as e inner join messages as m on m.email_id = e.id ' +
                    'set e.message_id = m.id, ' +
                    'e.sender_id = m.sender_id, ' +
                    'e.recipient_id = m.recipient_id;'
                ).then(() => {
                    queryInterface.dropTable('messages');
                });
            })
        })
    })
}

我不知道为什么 down（）仅执行第一个动作而不执行其他动作。这只是创建 sender_id 列。

有人可以帮我吗？我不知道我在做什么错。