客户端将图像上传到数据库，获取并发送给客户端

Question

我的设置：

RDBMS：postgreSQL

数据库名称：四个。

表：用户。

列：头像。

列数据类型：BLOB。

ORM：续集

其他事物包括表达，思考...不是那么重要。

...

问题：

将文件发送到数据库：

app.patch('/user/:id/avatar', upload.single('avatar'), async (req, res) => {
    const id = req.params.id

// encode file on base64
    const avatarBuffer = Buffer.from(req.file.buffer, 'base64')

// encode back to string to base64.
// the output is pretty much a base64 img. that if i put on any <img> tag src attribte works
    const avatarbase64 = avatarBuffer.toString('base64')

// update the avatar column for the user whose have the id fetched in the request params. (i used 3)
    await User.update({ avatar: avatarbase64 }, { where: { id } })

// i know there is no response on this route. this is pretty much to test the updload only.
})

从数据库中获取并作为响应发送给客户端。

app.get('/user/:id/avatar', async (req, res) => {
    try {

// fetching id from request params and fetching user whose has the image from database. 
// (i choose user 3 - the same user that i updated the image.)
        const id = req.params.id
        const user = await User.findOne({ where: { id } })

        if (!user) {
            throw new Error('unable to find user.')
        }


// on both cases I wrote a simple txt text with the base64 encoded image. 
// to check if its ok and it is. on both cases: upload and read, same code, work on any <img> tag.
        fs.writeFile('avatar.txt', user.avatar, () => {
            console.log('file written.')
        })

// set the head content type to accept jpg image (which is the type of the img i am uploading properly.)
        res.set('Content-type', 'image/jpg')

// sending to the client. 
        res.send(user.avatar)
    } catch (e) {
        res.status(404).send(e)
    }
})

好吧，我正在使用potman模拟这些请求，并且当我发送GET请求时，在POSTMAN上的输出是这样的：

如果我尝试使用Google chorme：

帮助* - *