How to save image data to sqflite database in flutter for persistence

Question

I\'m building a Flutter app where I would like to keep the data offline.

I\'m capturing an image using the camera or gallery image picker and able to store that image i

Answer 1

Images and, in general, files, are meant to be stored as BLOB in a SQLite database.

To do so:

1. We should create a Picture class:

class Picture {
 final int id;
 final String title;
 final Uint8List picture;

 Picture({this.id, this.title, this.picture});

 Picture.fromMap(Map map) {
   id = map[id];
   title = map[title];
   picture = map[picture];
 }

  Map toMap() => {
   "id": id,
   "title": title,
   "picture" : picture,
 };
}

2. We can then create our table accordingly:

await db.execute("CREATE TABLE Picture(id INTEGER PRIMARY KEY, title TEXT, picture BLOB )");

3. Create a method to save the Picture in the DB:

void savePicture(Picture picture) async {
  var dbClient = await db;
  await dbClient.insert("Picture", picture.toMap());
}

4. Create a method to get the Pictures from the DB:

Future> getPictures() async {
    var dbClient = await db;
    List

5. Save a Picture to the DB:

var image = await get(
  "https://images.pexels.com/photos/2047905/pexels-photo-2047905.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940");
var bytes = image.bodyBytes;
Picture picture = Picture(id, title, picture);
savePicture(picture);

6. Use it when needed, for example:

Image.memory(picture.picture);

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NB: While in the example above we used an Image, this concept applies well with any other kinds of files.

Converting a file to base64 and store it as a string works, but it's not the best solution. One issue is an increase of the storage requirements by 33%, that adds up quickly especially when dealing with large files.