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Android SQLite database is locked when pressing power button (screen off)

I'm getting a large amount of information from server and loading them in SQLite database (about 4000 rows). I'm using the following code to insert the info:
String DB_PATH = "/data/data/com.example.app.myapplication/databases/";
String DB_NAME = "mydb.sqlite";
SQLiteDatabase sqdb = SQLiteDatabase.openDatabase(DB_PATH + DB_NAME, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
try {
//Getting info
sqdb.beginTransaction();
String[] all_elements = all.split("_");
for (int j = 0; j < all_elements .length; j++) {
if (all_elements [j].length() >= 1) {
m.setLength(0);
m.append("insert into .....the query");
m.append(");");
sqdb.execSQL(m.toString().replaceAll("\n", "").replaceAll("\r", "").replaceAll("\t", ""));
changeProgressMessage("Adding element " + String.valueOf(j + 1) + "/" + String.valueOf(all_elements .length));
}
}
sqdb.setTransactionSuccessful();
sqdb.endTransaction();
}
catch (Exception ex)
{
Log.d("Error",ex.toString());
sqdb.setTransactionSuccessful();
sqdb.endTransaction();
}
The point is, when inserting the info, If I press the power button or the screen is off, The app crashes and I get an error saying that the database is locked.
Please note that I'm using another connection to the SQLite database but I'm closing it before using the second one.
db.openDataBase();
String[] array_elements = array.split("_");
for (int i = 0; i < array_elements .length; i++) {
String Details = "";
if (!array_elements [i].isEmpty() && !array_elements [i].equals("")) {
mbuilder.setLength(0);
mbuilder.append(array_elements [i] + ",'" + helper.getdatetime() + "'");
db.insertelements(mbuilder.toString(), "Element");
changeProgressMessage("Element" + String.valueOf(i + 1) + "/" + String.valueOf(array_elements .length) + " inserted");
}
}
db.close();
Any help please ?

Sorry Guys my bad, I was accessing the database in on resume method, so when turning off the screen then turning on, On resume method was called also the database method inside it which explains the crash.

Saving SQLite list as an array: Not Working [duplicate]

This question already has answers here:
Unfortunately MyApp has stopped. How can I solve this?
(23 answers)
Closed 7 years ago.
I have an SQLite Database, and within it, one of the columns stores Strings which include numbers. I am trying to retrieve the numbers, store them as doubles in an array, and then take the mean of the array. However, it's not working. The App crashes every time I get to that part. I know the problem has to be somewhere within the array because I am able to list the SQLite Database as a string.
public int getDataCount() {
String countQuery = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int cnt = cursor.getCount();
cursor.close();
return cnt;
}
public double databaseAverage(){
String dbString = "";
int dbInt = 0;
double dbDouble = 0;
SQLiteDatabase db = getWritableDatabase();
String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";
Cursor c = db.rawQuery(query, null);
c.moveToFirst();
int rowCount = getDataCount();
Double[] array = new Double[rowCount];
int i = 0;
while (!c.isAfterLast()) {
if (c.getString(c.getColumnIndex("productname")) != null) {
dbString += c.getString(c.getColumnIndex("productname"));
dbInt = Integer.parseInt(dbString.replaceAll("[\\D]",""));
dbDouble = (double) dbInt;
array[i] = dbDouble;
i++;
}
c.moveToNext();
}
db.close();
double sum = 0;
for(int v=0; v < array.length ; v++) {
sum = sum + array[i];
}
double average = sum / array.length;
return average;
}

please check your syntax :
String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE 1";
While it should be :
String query = "SELECT * FROM " + TABLE_PRODUCTS + " WHERE "+ {your coloumn name }+"=1";
Check above query in both methode getDataCount and databaseAverage

Getting SQLite DB data in 2d array and returning in android

I have the below function which I use to query the SQLite Db, put the retrieved records in to an array and return it back.
public String[][] getrecords(){
Log.i("SENDSERVER", "Get Records Called");
SQLiteDatabase sampleDB = this.getReadableDatabase();
Cursor c = sampleDB.rawQuery("SELECT id,welawa,lati,longi FROM " +
TABLE_LOCATIONS + " LIMIT 5", null);
String[][] aryDB = new String[5][4];
int i = 0;
if (c != null ) {
if (c.moveToFirst()) {
do {
String db_id = c.getString(c.getColumnIndex("id"));
String welawa = c.getString(c.getColumnIndex("welawa"));
String latitude = c.getString(c.getColumnIndex("lati"));
String longitude = c.getString(c.getColumnIndex("longi"));
aryDB[i][0] = db_id;
aryDB[i][1] = welawa;
aryDB[i][2] = latitude;
aryDB[i][3] = longitude;
Log.i("SENDSERVER", "Record Added"); //This doesn't get logged
i++;
}while (c.moveToNext());
}
}
Log.i("SENDSERVER", "Return Records");
return aryDB;
}
I try to retrieve the records and use them as below from my service class.
String aryDB[][] = dbh.getrecords();
Log.i("SENDSERVER", "GET DB RECORDS");
int i = 0;
int id = 0;
String welawa = "";
String lati = "";
String longi = "";
while(i < 5){
id = Integer.parseInt(aryDB[i][0]);
welawa = aryDB[i][1];
lati = aryDB[i][2];
longi = aryDB[i][3];
Log.i("SENDSERVERDB", id + " - " + welawa + " - " + lati + " - " + longi);
i++;
}
For some reason the array is not being returned.
My possible guesses are,
1. The defining of the function is wrong. My intention is to return the array.
2. I am getting the db connection / my retrieval code is wrong.
3. Some thing else that my noob brain can't comprehend.
Your help is greatly appreciated guys.
------EDIT
After adding some more logs the app crashes at
Cursor c = sampleDB.rawQuery("SELECT id,welawa,lati,longi FROM " +
TABLE_LOCATIONS + " LIMIT 5", null);
Any issue in my query?

It was a DB issue. Wrong ColumnName used.

The Cursor never returns null when there is no row which the requested conditions, just return a empty Cursor.
You code still has problem when the rawQuery returns 0 rows, cursor won't be null and do while loop will execute at least once.
So there will be problem on this line when the cursor is empty
c.getString(c.getColumnIndex("id"));
Change your code to this:
c.moveToFirst();
while (c.moveToNext())
{
String db_id = c.getString(c.getColumnIndex("id"));
String welawa = c.getString(c.getColumnIndex("welawa"));
String latitude = c.getString(c.getColumnIndex("lati"));
String longitude = c.getString(c.getColumnIndex("longi"));
aryDB[i][0] = db_id;
aryDB[i][1] = welawa;
aryDB[i][2] = latitude;
aryDB[i][3] = longitude;
Log.i("SENDSERVER", "Record Added"); //This doesn't get logged
i++;
}

Getting Exception Index 1 requested, with a size of 1

I am getting exception while fetching data from database in my android project. I am trying to get value of column index 1 from this line of code String ques=c.getString(1);
And this is the code where i am calling database class and trying to fetch database,
try{
c=db.getText(Integer.toString(subid));
if(c==null)
return;
//if(c.getCount()> 0)
//{
//int max=c.getCount();
//int min=0;
Random rn = new Random();
int randomNum = rn.nextInt(max-1) + rowid;
c.moveToPosition(randomNum);
String ques=c.getString(1);
tv.setText(ques+" ");
cans=c.getString(2);
shuffleArray(ans);
int[] a = new int[4];
int j=0;
for (int i = 0; i < ans.length; i++)
{
a[j]=ans[i];
j++;
}
ans1=c.getString(a[0]);
ans2=c.getString(a[1]);
ans3=c.getString(a[2]);
ans4=c.getString(a[3]);
rb1.setText(ans1);
rb2.setText(ans2);
rb3.setText(ans3);
rb4.setText(ans4);
}
catch(Exception e)
{
Toast.makeText(getApplicationContext(), e.getMessage()+"exception", Toast.LENGTH_LONG).show();
}
Snap shot of my database content,
this is my database class,
public Cursor getText(String subId) throws SQLException //here it'll get all rows of subId=1 or whatever the value of subId
{
Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] {
KEY_id, KEY_ques, KEY_correctans, KEY_wrongans1,KEY_wrongans2, KEY_wrongans3},
KEY_subjectid + "=" + " '" + subId + "' " , null,null,null, null,null);
if (mCursor != null)
{
mCursor.moveToFirst();
}
return mCursor;
}
Please help me and hope my question is clear.
Thanks in Advance.

You have an error:
Index 1 requested, with a size of 1
It says, that the size of your cursor is 1 and you know that indexing starts with 0. Therefore, if you write:
String ques = c.getString(1);
you try to get SECOND element, not the first one. If you want to get first element, you have to write:
String ques = c.getString(0);

Remove c.MovetoPosition(randomno);
Instead try this:
c.moveToFirst();
int rw_cnt=c.getCount();
int rndm = ((Math.random())*10000)%rw_cnt); //generates a random no btwn 1 and rw_cnt
for(int i=0;i<rndm;i++) //move cursor rand times
c.moveToNext();
This definitely would be slower than c.moveToPostion(); but it wouldn't make much of a difference unless you have thousands of rows

Fetching double value from Database and calculate with them

I got another weird problem which i just don't understand.
I am saving doubles into my database with max. 3 digits after the decimal point.
The doubles are stored in the database correctly but when i am trying to fetch the data and add/multiply the stored doubles i get a weird problem
If i am storing data with only one digit after the decimal point, everything works fine and i get the right results.
But if i am adding 2 or more digits after the decimal point my whole calculations won't work. I get no results into my TextViews.
I'm trying to understand whats happening for hours now but i just don't see why this happens.
Here is the code:
My MainActivity, where the TextViews get the Text:
public void calc() {
// Get text for the statistics
amount_widget.setText(db.getSearchResult("amount", 0));
lpayment_widget.setText(db.getSearchResult("price", 0));
tpayment_widget.setText(db.getSearchResult("total_price", 1));
mileage_widget.setText(db.getSearchResult("mileage", 2));
trefueled_widget.setText(db.getSearchResult("amount", 1));
// Calculate text for the consumption
double consumption = (Double.parseDouble(db
.getSearchResult("amount", 1)) / Double.parseDouble(db
.getSearchResult("mileage", 2))) * 100;
consumption = Math.round(consumption * 100) / 100.0;
consumption_widget.setText(consumption + "L /100km");
}
My Database Activity where the code is being fetched and calculated:
public String getSearchResult(String sql, int cmd) {
if (cmd == 0) {
String countQuery = "SELECT " + sql + " FROM " + TABLE_NAME
+ " WHERE _id = (SELECT max(_id) FROM " + TABLE_NAME + ")";
Cursor cursor = db.rawQuery(countQuery, null);
String tmp = cursor.moveToFirst() ? cursor.getString(0) : "0";
cursor.close();
return tmp;
} else if (cmd == 1) {
double sum = 0;
String countQuery = "SELECT " + sql + " FROM " + TABLE_NAME;
String idQuery = "SELECT _id FROM " + TABLE_NAME
+ " WHERE _id = (SELECT max(_id) FROM " + TABLE_NAME + ")";
Cursor cursor = db.rawQuery(countQuery, null);
Cursor id = db.rawQuery(idQuery, null);
// berechnung
cursor.moveToFirst();
id.moveToFirst();
int maxId = Integer.parseInt(id.getString(0));
for (int i = 0; i < maxId; i++) {
double tmp = Integer.parseInt(cursor.getString(0));
sum = sum + tmp;
cursor.moveToNext();
}
cursor.close();
id.close();
return String.valueOf(sum);
} else if (cmd == 2 && sql == "mileage") {
double sum = 0;
String countQuery = "SELECT " + sql + " FROM " + TABLE_NAME;
String idQuery = "SELECT _id FROM " + TABLE_NAME
+ " WHERE _id = (SELECT max(_id) FROM " + TABLE_NAME + ")";
Cursor cursor = db.rawQuery(countQuery, null);
Cursor id = db.rawQuery(idQuery, null);
// berechnung
cursor.moveToFirst();
id.moveToFirst();
int maxId = Integer.parseInt(id.getString(0));
if (maxId > 1) {
int array[] = new int[maxId];
// Array füllen
for (int i = 0; i < maxId; i++) {
array[i] = Integer.parseInt(cursor.getString(0));
// sum = sum + tmp;
cursor.moveToNext();
}
for (int k = 1; k < maxId; k++) {
double tmp;
tmp = array[k] - array[k - 1];
sum = sum + tmp;
}
cursor.close();
id.close();
return String.valueOf(sum);
} else {
return "--";
}
}
return "Wrong CMD";
}

Maybe you're making a simple mistake. Instead of:
consumption_widget.setText(consumption + "L /100km");
try this:
consumption_widget.setText(String.valueOf(consumption) + "L /100km");

I found my mistake.
In my DbAdapter class within the getSearchResult() method i have the following statement:
for (int i = 0; i < maxId; i++) {
double tmp = Integer.parseInt(cursor.getString(0));
sum = sum + tmp;
cursor.moveToNext();
}
Here I am trying to parse an Integer but write it into a double. This is why the calculations couldn't be executed. I need to parse a double like this:
for (int i = 0; i < maxId; i++) {
double tmp = Double.parseDouble(cursor.getString(0));
sum = sum + tmp;
cursor.moveToNext();
}
this is the solution to my problem