I am very new to creating and manipulating databases and I seem to be stuck, my logcat keeps telling me that it cannot open the database?
09-12 13:02:31.823: I/SqliteDatabaseCpp(7213): sqlite returned: error code = 14, msg = cannot open file at line 27701 of [8609a15dfa], db=/data/data/net.learn2develop.Database/databases/database
Im guessing it cannot find it but i am usure why. Thanks to many of you on here i have worked my way this far but am still getting stuck, What my code is doing is importing a database i made from the assets folder. Here is my database helper class:
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String KEY_ROWID = "_id";
public static final String KEY_ALCOHOL = "alcohol";
public static final String KEY_TYPE = "type";
public static final String KEY_BRAND = "brand";
public static final String KEY_PRICE = "price";
private static final String TAG = "DatabaseHelper";
private static String DB_PATH = "/data/data/net.learn2develop.Database/databases/";
private static String DB_NAME = "database";
private static final String DB_TABLE = "booze";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase myDataBase) {
}
@Override
public void onUpgrade(SQLiteDatabase myDataBase, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion
+ " to "
+ newVersion + ", which will destroy all old data");
myDataBase.execSQL("DROP TABLE IF EXISTS titles");
onCreate(myDataBase);
}
//---insert a title into the database---
public long insertTitle(String alcohol, String type, String brand, int price)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_ALCOHOL, alcohol);
initialValues.put(KEY_TYPE, type);
initialValues.put(KEY_BRAND, brand);
initialValues.put(KEY_PRICE, price);
return myDataBase.insert(DB_TABLE, null, initialValues);
}
//---retrieves a particular title---
public Cursor getTitle(long rowId) throws SQLException
{
Cursor mCursor =
myDataBase.query(true, DB_TABLE, new String[] {
KEY_ROWID,
KEY_ALCOHOL,
KEY_TYPE,
KEY_BRAND,
KEY_PRICE
},
KEY_ROWID + "=" + rowId,
null,
null,
null,
null,
null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
Here is what I am calling in my activity as a test to see if i can read the DB:
public class DatabaseActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_database);
DatabaseHelper myDbHelper = new DatabaseHelper(this);
//---get a title---
myDbHelper.openDataBase();
Cursor c = myDbHelper.getTitle(2);
if (c.moveToFirst())
DisplayTitle(c);
else
Toast.makeText(this, "No title found",
Toast.LENGTH_LONG).show();
myDbHelper.close();
}
public void DisplayTitle(Cursor c)
{
Toast.makeText(this,
"id: " + c.getString(0) + "\n" +
"ALCOHOL: " + c.getString(1) + "\n" +
"TYPE: " + c.getString(2) + "\n" +
"BRAND: " + c.getString(3) + "\n" +
"PRICE: " + c.getString(4),
Toast.LENGTH_LONG).show();
}
}
The name of my database i created is just “database”, the activity is “DatabaseActivity.java” and the helper file is “DatabaseHelper.java”
Here is what my database looks like
You should always post all of your Logcat errors, but I think I see the problem.
You have already opened the SQLiteDatabase behind the scenes in your DatabaseHelper constructor, now you want to access it. Try this:
Did you ever copy your database from the asset folder?
If you haven’t done this, then the database won’t exist in the
database/folder and cannot be opened…