sequelize in node JS combines with mysql to realize adding, querying, modifying and deleting

1. Sequelize in node JS combines with mysql to realize adding, querying, modifying and deleting

1. sequelizeCombined mysqlto achieve increased create.jscode as follows:

const {
    
     Blog, User } = require('./model')

!(async function () {
    
    

  // 创建用户
  const zhangsan = await User.create({
    
    
    userName: 'zhangsan',
    password: '123',
    nickName: '张三'
  })

  // insert into users (...) values (...)
  console.log('zhangsan: ', zhangsan.dataValues)
  const zhangsanId = zhangsan.dataValues.id

  const lisi = await User.create({
    
    
    userName: 'lisi',
    password: '123',
    nickName: '李四'
  })
  const lisiId = lisi.dataValues.id


  // 创建博客
  const blog1 = await Blog.create({
    
    
    title: '标题1',
    content: '内容1',
    userId: zhangsanId
  })
  console.log('blog1', blog1.dataValues)

  const blog2 = await Blog.create({
    
    
    title: '标题2',
    content: '内容2',
    userId: zhangsanId
  })

  const blog3 = await Blog.create({
    
    
    title: '标题3',
    content: '内容3',
    userId: lisiId
  })

  const blog4 = await Blog.create({
    
    
    title: '标题4',
    content: '内容4',
    userId: lisiId
  })

})()

2. sequelizeBinding mysqlachieved query select.jscode as follows:

const {
    
     User, Blog } = require('./model')

!(async function () {
    
    
  // 查询一条记录
  // const zhangsan = await User.findOne({
    
    
  //   where: {
    
    
  //       userName: 'zhangsan'
  //   }
  // })
  // console.log('zhangsan', zhangsan.dataValues )

  // 查询特定的列
  // const zhangsanName = await User.findOne({
    
    
  //   attributes: ['userName', 'nickName'],
  //   where: {
    
    
  //     userName: 'zhangsan'
  //   }
  // })
  // console.log('zhangsanName', zhangsanName.dataValues)

  // 查询一个列表
  // const zhangsanBlogList = await Blog.findAll({
    
    
  //   where: {
    
    
  //     userId: 1
  //   },
  //   order: [
  //     ['id', 'desc']
  //   ]
  // })
  // console.log('zhangsanBlogList', zhangsanBlogList.map(blog => blog.dataValues))

  // 分页
  // const blogPageList = await Blog.findAll({
    
    
  //   limit: 2, // 限制本次查询 2 条，每页显示的条数
  //   offset: 2, // 跳过多少条，从第几页开始
  //   order: [
  //     ['id', 'desc']
  //   ]
  // })
  // console.log('blogPageList', blogPageList.map(blog => blog.dataValues))

  // 查询总数
  // const blogListAndCount = await Blog.findAndCountAll({
    
    
  //   limit: 2,
  //   offset: 2,
  //   order: [
  //     ['id', 'desc']
  //   ]
  // })
  // console.log('blogListAndCount', 
  //           blogListAndCount.count, // 所有的总数，不考虑分页
  //           blogListAndCount.rows.map(blog => blog.dataValues)
  //         )

  // 连表查询 1
  // 先有 blog，后有 user
  // const blogListWithUser = await Blog.findAndCountAll({
    
    
  //   order: [
  //     ['id', 'desc']
  //   ],
  //   include: [
  //     {
    
    
  //       model: User,
  //       attributes: ['userName', 'nickName'],
  //       where: {
    
    
  //         userName: 'zhangsan'
  //       }
  //     }
  //   ]
  // })
  // console.log('blogListWithUser',
  //           blogListWithUser.count,
  //           blogListWithUser.rows.map(blog => {
    
    
  //             const blogVal = blog.dataValues
  //             blogVal.user = blogVal.user.dataValues
  //             return blogVal
  //           })
  //         )


  // 连表查询 2
  const userListWithBlog = await User.findAndCountAll({
    
    
    attributes: ['userName', 'nickName'],
    include: [
      {
    
    
        model: Blog
      }
    ]
  })
  console.log('userListWithBlog',
            userListWithBlog.count,
            userListWithBlog.rows.map(user => {
    
    
              const userVal = user.dataValues
              userVal.blogs = userVal.blogs.map(blog => blog.dataValues)
              return userVal
            })
        )

})()

3. sequelizeBinding mysqlachieved modify update.jscode as follows:

const {
    
     User } = require('./model')

!(async function () {
    
    

  const updateRes = await User.update({
    
    
    nickName: '张三1'
  }, {
    
    
    where: {
    
    
      userName: 'zhangsan'
    }
  })
  console.log('updateRes', updateRes[0] > 0)

})()

4. sequelizeBinding mysqlachieved deleted delete.jscode as follows:

const {
    
     User, Blog } = require('./model')

!(async function () {
    
    
  // 删除一条博客
  const deleteBlogRes = await Blog.destroy({
    
    
    where: {
    
    
      id: 4
    }
  })
  console.log('deleteBlogRes', deleteBlogRes > 0)

  // 删除一个用户
  const deleteUserRes = await User.destroy({
    
    
    where: {
    
    
      id: 1
    }
  })
  console.log('deleteUserRes', deleteUserRes)

})()