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

You can convert an image to BASE64 and store image as a string in your database. Check this link and this one

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<String, dynamic> 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<List<Picture>> getPictures() async {    var dbClient = await db;    List<Map> list = await dbClient.rawQuery('SELECT * FROM Picture');    List<Picture> pictures = new List();    for (int i = 0; i < list.length; i++) {      pictures.add(new Picture(list[i]["id"], list[i]["text"], list[i]["picture"]));    }    return pictures;  }}

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);

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.