How to use read and write streams in node.js for BIG CSV files

Поделиться
HTML-код
  • Опубликовано: 31 дек 2024

Комментарии • 30

  • @sameerbharadwaj11
    @sameerbharadwaj11 2 года назад +3

    Thank You! This helped a lot with writing 20mil records to solr.

    • @WebDevCody
      @WebDevCody  2 года назад

      Oh wow this actually helped? I’m glad 😂

  • @GabrielAugustoDeVito
    @GabrielAugustoDeVito Месяц назад

    Great explaination ty

  • @thetchana
    @thetchana Месяц назад

    Thank You!

  • @martinmingosuarez8690
    @martinmingosuarez8690 2 года назад +16

    there is a core module called readline that works with streams to read one line at a time, no need to write the logic yourself, otherwise great explanation and video. Cheers

    • @veremox
      @veremox 2 года назад

      im not an expert but a chunk is not necessarily a line...

    • @oscarmamani5996
      @oscarmamani5996 Год назад

      martinmingosuarez8690 thank you for this comment! it help me

    • @LegendKopper
      @LegendKopper Год назад

      -----The topic "NodeJS streams---->
      (your head)

  • @officialabdulrehman
    @officialabdulrehman 2 года назад

    This was very helpful. Thank you

  • @pranjaldoorwar9743
    @pranjaldoorwar9743 2 года назад +3

    This might be helpful to me i am trying to read csv data and insert it into mongodb first before parsing it

  • @PhuTran-nb7me
    @PhuTran-nb7me 2 года назад +3

    Hello Sir, I have a question, much appreciated If you can address my doubt. Do chunks come in sequence, in other words, does the read stream wait for the current chunk to finish the operations before it emit the "data" event to process the next chunk? You have a potentially long running iteration there and more importantly, each chunk is interdependent to each other as the last If statement is used to assign the last incomplete row to "unprocessed" variable for the next chunk to use.

    • @WebDevCody
      @WebDevCody  2 года назад +2

      Yes they should come in order.

    • @empty8537empty
      @empty8537empty 2 года назад +2

      It should be in order..which is taken care by your transport layer..

  • @ViktosB
    @ViktosB 10 месяцев назад +1

    Hi, I really enjoy your videos. One of the most productive publisher on RUclips. But in that video the name "overWatermark" is highly misleading. I struggled understand the whole structure only because of that naming. This would be better if you use instead "canWrite". canWrite is true when we can write and false when the buffer is full. Then we stop -> !canWrite.
    const canWrite = writeStream.write(`${i},
    `);
    if (!canWrite) {
    await new Promise((resolve) => writeStream.once('drain', resolve));
    }
    }
    I might be wrong of course.
    Other than that - great job again. Continue watching you content 🙂

  • @LarsRyeJeppesen
    @LarsRyeJeppesen Год назад

    Super stuff, thanks. Subbed

  • @bipinshukla5222
    @bipinshukla5222 2 года назад

    Awesome explaination

  • @vpetryniak
    @vpetryniak 5 месяцев назад

    How to use Web stream API in node js to do the same thing?

  • @Tony.Nguyen137
    @Tony.Nguyen137 5 месяцев назад

    What if I want to read big data of users - User{age:20………height:7“} - and save it into a database, but that chunk of data miss some properties that a user have like age:20“ ? Could this happen if yes how to solve it

  • @CarlosHonorioBriones
    @CarlosHonorioBriones 2 года назад

    nice! This is good to know. Thanks!

  • @rorycawley
    @rorycawley 2 года назад

    Great video, thanks

  • @ПетърТодоров-о7ф

    thank u, buddy!

  • @YOUdudex
    @YOUdudex 2 года назад

    Cool video, thanks subscribed

  • @mtuchidev
    @mtuchidev Год назад

    How do you pass a chunk size ?

  • @lucanthony2209
    @lucanthony2209 2 года назад

    Hello @vJunkie,
    Thanks for the great content.
    CAn you make a video using csv-parser & fs libraries to read & write csv files ?

  • @SeibertSwirl
    @SeibertSwirl 2 года назад

    Good job babe!!!

  • @haohong5141
    @haohong5141 Год назад

    node version?

  • @himaliamit8698
    @himaliamit8698 2 года назад

    if you show us the format of the csv file it would have made much more sense.

    • @majidshah48
      @majidshah48 2 года назад

      i think opening the file will take time or it might just crash

  • @boople2snoot
    @boople2snoot 2 года назад

    them jump cuts

    • @boople2snoot
      @boople2snoot 2 года назад

      also no sub, your variable is overWatermark, you're waiting for an event emitter if not overWatermark, the function therefore must return true if it is not over the watermark and var should be named underWatermark. Or it would run if not overWatermark, which is under the watermark, which? shit you just ramble, bye.