How to Store and Retrieve a Byte Array (Image Data) to and from a SQLite Database

Best method to save & retrieve images to database

Yes, it's definitely possible to do, but you could also use Blobs as well (see this post How to store and retrieve a byte array (image data) to and from a SQLite database?). If you want to store the images as Base64 strings, though, it's pretty easy to do, just use the Apache library to encode the raw image bytes[] to a Base64 String.

Here's the reference: Apache Base 64

First you'll want to encode the image bytes[] using public static String encodeBase64String(byte[] binaryData).

Then, you can store the Base64 String in your database.

When you go to retrieve the image, just use public static byte[] decodeBase64(String base64Data)
to convert the String back to bytes[], and use the BitmapFactory to get the Bitmap.

Edit:

Played around with this for a bit, and for some reason after adding the core commons-codec-1.9.jar, I get a java.lang.NoSuchMethodError. In case this problem isn't specific to my build, it's the same as:

String base64string = new String(Base64.encodeBase64(drawable), "UTF-8");

How to store(bitmap image) and retrieve image from sqlite database in android?

Setting Up the database

public class DatabaseHelper extends SQLiteOpenHelper {
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "database_name";

    // Table Names
    private static final String DB_TABLE = "table_image";

    // column names
    private static final String KEY_NAME = "image_name";
    private static final String KEY_IMAGE = "image_data";

    // Table create statement
    private static final String CREATE_TABLE_IMAGE = "CREATE TABLE " + DB_TABLE + "("+ 
                       KEY_NAME + " TEXT," + 
                       KEY_IMAGE + " BLOB);";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        // creating table
        db.execSQL(CREATE_TABLE_IMAGE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // on upgrade drop older tables
        db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);

        // create new table
        onCreate(db);
    }
}

Insert in the Database:

public void addEntry( String name, byte[] image) throws SQLiteException{
    SQLiteDatabase database = this.getWritableDatabase();
    ContentValues cv = new  ContentValues();
    cv.put(KEY_NAME,    name);
    cv.put(KEY_IMAGE,   image);
    database.insert( DB_TABLE, null, cv );
}

Retrieving data:

 byte[] image = cursor.getBlob(1);

Note:

1. Before inserting into database, you need to convert your Bitmap image into byte array first then apply it using database query.
2. When retrieving from database, you certainly have a byte array of image, what you need to do is to convert byte array back to original image. So, you have to make use of BitmapFactory to decode.

Below is an Utility class which I hope could help you:

public class DbBitmapUtility {

    // convert from bitmap to byte array
    public static byte[] getBytes(Bitmap bitmap) {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(CompressFormat.PNG, 0, stream);
        return stream.toByteArray();
    }

    // convert from byte array to bitmap
    public static Bitmap getImage(byte[] image) {
        return BitmapFactory.decodeByteArray(image, 0, image.length);
    }
}

Further reading

If you are not familiar how to insert and retrieve into a database, go through this tutorial.

How to store image in SQLite database

You have to use "blob" to store image.

ex: to store a image in to db:

public void insertImg(int id , Bitmap img ) {   

    byte[] data = getBitmapAsByteArray(img); // this is a function

    insertStatement_logo.bindLong(1, id);       
    insertStatement_logo.bindBlob(2, data);

    insertStatement_logo.executeInsert();
    insertStatement_logo.clearBindings() ;

}

 public static byte[] getBitmapAsByteArray(Bitmap bitmap) {
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
    bitmap.compress(CompressFormat.PNG, 0, outputStream);       
    return outputStream.toByteArray();
}

To retrieve a image from db:

public Bitmap getImage(int i){

    String qu = "select img  from table where feedid=" + i ;
    Cursor cur = db.rawQuery(qu, null);

    if (cur.moveToFirst()){
        byte[] imgByte = cur.getBlob(0);
        cur.close();
        return BitmapFactory.decodeByteArray(imgByte, 0, imgByte.length);
    }
    if (cur != null && !cur.isClosed()) {
        cur.close();
    }       

    return null;
} 

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