Question

I have created a database for my android app which contains static data and does not require update/delete functionality thus when the app starts, I want to check if the db exists and if not then execute my dbAdapter class. I know its a simple if statement but I was just wondering the most efficient way to query whether the db exists.

Cheers

Answer 1

/**
 * Check if the database exist and can be read.
 * 
 * @return true if it exists and can be read, false if it doesn't
 */
private boolean checkDataBase() {
    SQLiteDatabase checkDB = null;
    try {
        checkDB = SQLiteDatabase.openDatabase(DB_FULL_PATH, null,
                SQLiteDatabase.OPEN_READONLY);
        checkDB.close();
    } catch (SQLiteException e) {
        // database doesn't exist yet.
    }
    return checkDB != null;
}

where DB_FULL_PATH is the path to your database file.

And the reason I am not just checking if a file exists is because it would not tell whether (a) it’s an sqlite db file, (b) the file is not corrupt and can actually be read, i.e. due to partial download or however it has been created.