Save images on sqlite android

Question

Save images on sqlite android

Navigation

#1 by (2 votes)
#2 by (1 votes)

5

Hello, I am trying an example to save photos in sqlite, I have managed to show an image of the gallery, but I do not know how to save it. Thanks.

//cargar foto en imagenView
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
    if(resultCode == RESULT_OK && requestCode == RESULT_LOAD_IMAGE){
        imageUri = data.getData();
        IMGView.setImageURI(imageUri);

        //pasar a mapa de bits
        Bitmap bitmap = IMGView.getDrawingCache();
    }
}

java android blob sqlite

asked by Daniel Zambrana 30.05.2017 в 13:22

source

2 answers

UPDATE from a SELECT using SQL Server Update the database when I move rows of a table

score 2 · Answer 1

If it is better to save the image in a Datatype Blob, or in a file with the route as a reference in the table depends on the size of your images.

You can find a table that indicates how large a square can be saved directly in the table at this page As you can see, up to a size of 20k it is always possible to save the direct Blob, with larger sizes that depends on the page size in the access to SQLite.

The versions of SQLite used on Android are currently all earlier than 3.12 , meaning that the default page size is 1024 bytes.

To change the page size you can use PRAGMA , before to create the table :

PRAGMA page_size = 4096;

(The Pragma can for example add in onCreate of your SQLiteOpenHelper )

The procedure to save images from Bitmap would be:

compress the bitmap by ByteArrayOutputStream
write the byte[] of the stream as blob in your table:
a CREATE TABLE imagenes (id INTEGER PRIMARY KEY, img BLOB); table is assumed with a SQLiteOpenHelper helper

In code:

public void guardarImagen(long id, Bitmap bitmap){
    // tamaño del baos depende del tamaño de tus imagenes en promedio
    ByteArrayOutputStream baos = new ByteArrayOutputStream(20480);
    bitmap.compress(Bitmap.CompressFormat.PNG, 0 , baos);
    byte[] blob = baos.toByteArray();
    // aqui tenemos el byte[] con el imagen comprimido, ahora lo guardemos en SQLite
    SQLiteDatabase db = helper.getWritableDatabase();

    String sql = "INSERT INTO imagenes (id, img) VALUES(?,?)";
    SQLiteStatement insert = db.compileStatement(sql);
    insert.clearBindings();
    insert.bindLong(1, id));
    insert.bindBlob(2, blob);
    insert.executeInsert();
    db.close();
}

To recover an image according to id you can use:

public Bitmap buscarImagen(long id){
    SQLiteDatabase db = helper.getReadableDatabase();

    String sql = String.format("SELECT * FROM imagenes WHERE id = %d", id);
    Cursor cursor = db.rawQuery(sql, new String[] {});
    Bitmap bitmap = null;
    if(cursor.moveToFirst()){
        byte[] blob = cursor.getBlob(1);
        ByteArrayInputStream bais = new ByteArrayInputStream(blob);
        bitmap = BitmapFactory.decodeStream(bais);
    }
    if (cursor != null && !cursor.isClosed()) {
        cursor.close();
    }
    db.close();
    return bitmap; 
}

score 1 · Answer 2

To save an image in a database you must save the path of the file. That is to say that when you make a insert of the image to the BD you must do the insert of the route. You should also keep in mind that the file is copied to the file of your app.