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两部分问题。
第 1 部分:
我正在将图像上传到我的服务器并希望将其保存到我的数据库中。
迄今为止:
table :
解析器:
registerPhoto: inSequence([
async (obj, { file }) => {
const { filename, mimetype, createReadStream } = await file;
const stream = createReadStream();
const t = await db.images.create({
Name: 'test',
imageData: stream ,
});
},
])
Executing (default): INSERT INTO `images` (`Id`,`imageData`,`Name`) VALUES (DEFAULT,?,?);
最佳答案
这花了我一些时间,但我终于想通了。
第一步(保存到数据库):
必须获取整个流数据并像这样读取它:
export const readStream = async (stream, encoding = 'utf8') => {
stream.setEncoding('base64');
return new Promise((resolve, reject) => {
let data = '';
// eslint-disable-next-line no-return-assign
stream.on('data', chunk => (data += chunk));
stream.on('end', () => resolve(data));
stream.on('error', error => reject(error));
});
};
const streamData = await readStream(stream);
const buff = Buffer.from(streamData);
db.images.create(
{
Name: filename,
imageData: buff,
Length: stream.bytesRead,
Type: mimetype,
},
{ transaction: param }
);
Length
和
Type
参数,如果您想在返回图像时返回流,则需要此参数。
const handler = async (req, reply) => {
const p: postParams = req.params;
const parser = uuIdParserT();
const img = await db.images.findByPk(parser.setValueAsBIN(p.id));
const binary = img.dataValues.imageData.toString('binary');
const b = Buffer.from(binary);
const myStream = new Readable({
read() {
this.push(Buffer.from(binary));
this.push(null);
},
});
reply.send(myStream);
};
export default (server: FastifyInstance) =>
server.get<null, any>('/:id', opts, handler);
useEffect(() => {
// axiosState is the obj that holds the image
if (!axiosState.loading && axiosState.data) {
// @ts-ignore
const b64toBlob = (b64Data, contentType = '', sliceSize = 512) => {
const byteCharacters = atob(b64Data);
const byteArrays = [];
for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {
const slice = byteCharacters.slice(offset, offset + sliceSize);
const byteNumbers = new Array(slice.length);
// @ts-ignore
// eslint-disable-next-line no-plusplus
for (let i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
const byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
const blob = new Blob(byteArrays, { type: contentType });
return blob;
};
const blob = b64toBlob(axiosState.data, 'image/jpg');
const urlCreator = window.URL || window.webkitURL;
const imageUrl = urlCreator.createObjectURL(blob);
setimgUpl(imageUrl);
}
}, [axiosState]);
<img src={imgUpl} alt="NO" className="imageUpload" />
关于mysql - 如何在mysql中保存和检索图像?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61900626/
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