Storing file in PostgreSQL database using NestJS

Question

I have one form in React. It has many fields. once user click on the submit button all the field should be saved in database. It also contains one file attachment(pdf).

I dont know what the datatype of variable which will store file, I should take in entity class. Also what should be the database column type. I am using TypeORM for the same.

   @IsNotEmpty()
    @IsDate()
    endDate: Date;
    @Column()
    @IsNotEmpty()
    @IsString()
    personIncharge: string;

    @Column()
    @IsNotEmpty()
    @IsString()
    country: string;

    @Column()
    @IsNotEmpty()
    @IsString()
    comments: string;

    attachFile: string;  // Should I take file or string?

Answer 1

You will probably find your solution in this StackOverflow comment

Basically, you turn your column type in a blob or longblob in your TypeORM annotation, and then use the type Buffer in your Entity's field

@Column({type: 'longblob'})
attachFile: Buffer;

Then you will be able to serve the file as showed in the post example:

app.get("/file/:id", async (req, res)=>{
    try {
        const repo = getConnection().getRepository(MYFile)
        const result_find = await repo.findOne(req.params.id)
        console.log(result_find);
        var fileData = result_find.data;
        res.writeHead(200, {
        'Content-Type': result_find.mimeType,
        'Content-Disposition': 'attachment; filename=' + result_find.name,
        'Content-Length': fileData.length
        });
        res.write(fileData);
        res.end();
    } catch (error) {
        console.log(error)
        res.send("ERROR")
    }
})