Develop Reference

Why is my jpql .getResultList() returning 0 rows for a good query

I was using the exact same query yesterday and it was working fine today I made a few changes to flow of the program and the query no longer returns and rows.
the first function that my programs goes to:
public void prepareSummary(Date startDate , Date endDate)
{
int getStartDay = getDayFromDate(startDate);
int getStartMonth = getMonthFromDate(startDate);
//
int getEndDay = getDayFromDate(endDate);
int getEndMonth = getMonthFromDate(endDate);
int getYear = getYearFromDate(startDate);
if(getStartMonth <= getEndMonth)
{
if(getStartMonth == getEndMonth)
{
if(getStartDay < getEndDay)
{
while(getStartDay <= getEndDay)
{
Calendar cal = Calendar.getInstance();
cal.set( getYear, getStartMonth, getStartDay);
Date queryStart = getStartOfDay(cal.getTime());
Date queryEnd = getEndOfDay(cal.getTime());
List<Object[]> res = getSumList(queryStart, queryEnd);
doQuery(res);
++getStartDay;
}
}
else
{
}
}
else
{
}
}
else
{
}
}
Here is what getSumList looks like:
public List<Object[]> getSumList(Date start, Date end) {
String query = "";
query += "SELECT COUNT(s) pCount,"
+ "p.nameText,"
+ "g.nameText,"
+ "t.shiftID"
+ " FROM Sheets s , GradeNames g , SpecieNames p, ShiftTimes t"
+ " WHERE s.createdLocal > :start and s.createdLocal < :end"
+ " AND s.specieNameIndex = p.nameIndex "
+ " AND s.gradeNameIndex = g.nameIndex"
+ " AND s.shiftIndex = t.shiftIndex"
+ " GROUP BY p.nameText , g.nameText , t.shiftID";
Query q = em.createQuery(query);
q.setParameter("start", start);
q.setParameter("end", end);
return q.getResultList();
}
This next function doesn't matter at this point because nothing is being executed because the list length is zero:
private void doQuery(List<Object[]> obj)
{
int length = obj.size();
String grade = null;
Long standingCount = (long) 0;
System.out.println("Length" + length);
for (int i = 0; i < length; ++i) {
// HAVE A LIST OF ALL ITEMS PULLED FROM DATABASE
Object[] tmpObj = obj.get(i);
Long tmpCount = (Long) tmpObj[0];
String tmpSpecieName = (String) tmpObj[1];
Double tmpThickness = Double.parseDouble(getSpecie().getThicknessFromSpecie(tmpSpecieName));
String tmpLength = getSpecie().getLengthFromSpecie(tmpSpecieName);
String tmpGradeName = (String) tmpObj[2];
String tmpShift = (String) tmpObj[3];
tmpSpecieName = getSpecie().getSpecieFromSpecie(tmpSpecieName);
//// END OF ALL ITEMS PULLED FROM DATABASE
if (grade != pullGradeName(tmpGradeName) && grade != null) {
System.out.println("Count:" + standingCount + "Grade:" + tmpGradeName + "--" + "Specie" + tmpSpecieName + "Shift:" + tmpShift + "Thickness:" + tmpThickness + "Length:" + tmpLength + "SpecieNAme:" + tmpSpecieName);
// do previous insert
grade = pullGradeName(tmpGradeName);
} else if (grade != pullGradeName(tmpGradeName) && grade == null) {
grade = pullGradeName(tmpGradeName);
} else if (grade == pullGradeName(tmpGradeName)) {
standingCount = standingCount + tmpCount;
}
System.out.println("Count:" + tmpCount + "Grade:" + tmpGradeName + "--" + "Specie" + tmpSpecieName + "Shift:" + tmpShift + "Thickness:" + tmpThickness + "Length:" + tmpLength + "SpecieNAme:" + tmpSpecieName);
}
}

Check the SQL that is generated, and the tables you are querying over. As the query requires inner joins, if one of the tables was cleared, it would return no results. If you want to get a 0 count, you need to use an outer join syntax which isn't possible in JPA unless you use object level mappings:
"SELECT COUNT(s) pCount,"
+ "p.nameText,"
+ "g.nameText,"
+ "t.shiftID"
+ " FROM Sheets s outer join s.specialNameIndex p,"
+ " outer join s.gradeNameIndex g, outer join s.shiftIndex t"
+ " WHERE s.createdLocal > :start and s.createdLocal < :end"
+ " GROUP BY p.nameText , g.nameText , t.shiftID";

Optimize performance java "for" and "array string"

I had problems with the slowness of this code.
I tried to optimize it for make it faster but I could not.
Can you give me some suggestions?
This is the part of the java code:
public ArrayList<String> kcal_spu(String tipo_pasto, String data) {
kcal_spuntino = new ArrayList<String>();
id_cibi_colazione = DiarioDataBaseAdapter.getId(tipo_pasto, data);
porzione_n2_colazione = DiarioDataBaseAdapter.getPorzione(tipo_pasto, data);
ArrayList<?> kcal2 = DiarioDataBaseAdapter.getKcal2(tipo_pasto, data);
int size = id_cibi_colazione.size();
int j = 0;
for (int i = 0; i < size; i++) {
double num_porz = Double.parseDouble(porzione_n2_colazione.get(j));
String getkcal = FoodDataBaseAdapter.getKcal(id_cibi_colazione.get(j));
String id_check = id_cibi_colazione.get(j);
if (id_check.equals("null")) {
double kcal_porz = Double.parseDouble(kcal2.get(j).toString());
double result = num_porz * kcal_porz;
kcal_spuntino.add("" + (int) result);
j = j + 1;
} else {
double kcal_porz = Double.parseDouble(getkcal);
double result = num_porz * kcal_porz;
kcal_spuntino.add("" + (int) result);
j = j + 1;
}
}
return kcal_spuntino;
}
This is the function DiarioDataBaseAdapter.getId:
public ArrayList getId(String tipo_pasto, String data) {
ArrayList array_list = new ArrayList();
Cursor res = db.rawQuery("SELECT ID_CIBO from Diario_Cibo where TIPO_PASTO = '" + tipo_pasto + "' AND DATA = '" + data + "'", null);
res.moveToFirst();
while (res.isAfterLast() == false) {
array_list.add(res.getString(res.getColumnIndex("ID_CIBO")));
res.moveToNext();
}
if (res != null) {
res.close();
}
return array_list;
}
This is the function DiarioDataBaseAdapter.getPorzione:
public ArrayList getPorzione(String tipo_pasto, String data) {
ArrayList array_list = new ArrayList();
Cursor res = db.rawQuery("SELECT PORZIONE from Diario_Cibo where TIPO_PASTO = '" + tipo_pasto + "' AND DATA = '" + data + "'", null);
res.moveToFirst();
while (res.isAfterLast() == false) {
array_list.add(res.getString(res.getColumnIndex("PORZIONE")));
res.moveToNext();
}
if (res != null) {
res.close();
}
return array_list;
}
This is the function DiarioDataBaseAdapter.getKcal2:
public ArrayList getKcal2(String tipo_pasto, String data) {
ArrayList array_list = new ArrayList();
Cursor res = db.rawQuery("SELECT KCAL from Diario_Cibo where TIPO_PASTO = '" + tipo_pasto + "' AND DATA = '" + data + "'", null);
res.moveToFirst();
while (res.isAfterLast() == false) {
array_list.add(res.getString(res.getColumnIndex("KCAL")));
res.moveToNext();
}
if (res != null) {
res.close();
}
return array_list;
}
Thanks in advance.

Your database queries will be the slowest part and there are three of them. Without profiling the code I would start with looking at the database selects and the tables to make sure they have the correct indexes on them for efficient searching.
Otherwise even putting a simple nanosecond timer in the code will give you an idea of what is taking the most time.
eg.
System.nanoTime():
long start = System.nanoTime();
// do stuff
long end = System.nanoTime();
System.out.println("time " + (end -start));

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++;
}

If + try - catch in method not working properly

I'm working on an SQLite based app. Everything is working fine, except my if-else statements in my method. The saving and stuff works, just the checking is giving me a pretty high blood pressure. I'm hoping one of you is much smarter than i am and finds the probably obvious mistake i made:
public void save() {
// get length of EditText
int dateLength, mileageLength, amountLength, lpriceLength, tpriceLength;
dateLength = date_widget.getText().length();
mileageLength = mileage_widget.getText().length();
amountLength = amount_widget.getText().length();
lpriceLength = price_widget.getText().length();
tpriceLength = totalPrice_widget.getText().length();
// Start save method if EditTexts are not empty.
if (dateLength > 0 || mileageLength > 0 || amountLength > 0
|| lpriceLength > 0 || tpriceLength > 0) {
// Get the value of each EditText and write it into the
// String/doubles
String date = date_widget.getText().toString();
double mileage = Double
.valueOf(mileage_widget.getText().toString());
double amount = Double.valueOf(amount_widget.getText().toString());
double lprice = Double.valueOf(price_widget.getText().toString());
double tprice = Double.valueOf(totalPrice_widget.getText()
.toString());
// Check if mileage is increasing, else cancel and show toast
int checkMileage = Integer.parseInt(db
.getSearchResult("mileage", 0));
if (checkMileage < mileage) {
try {
// if (id == null) {
db.insert(date, mileage, amount, lprice, tprice);
Toast.makeText(this, R.string.action_input_saved,
Toast.LENGTH_SHORT).show();
finish();
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(this, "ERROR " + e, Toast.LENGTH_LONG)
.show();
}
} else {
Toast.makeText(
this,
"Your current mileage must be more than the last saved mileage",
Toast.LENGTH_LONG).show();
}
} else {
Toast.makeText(this, "finish your input", Toast.LENGTH_LONG).show();
}
}
My Method in the DbAdapter class:
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);
cursor.moveToFirst();
String tmp = cursor.getString(0);
cursor.close();
// return count
return tmp;
} else if (cmd == 1) {
int 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++) {
int 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") {
int 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++) {
int tmp;
tmp = array[k] - array[k - 1];
sum = sum + tmp;
}
cursor.close();
id.close();
return String.valueOf(sum);
} else {
return "--";
}
}
return "Wrong CMD";
}
I is pretty messy, i know

Turning comment into an answer:
Switch all || to && in your first if. Otherwise you will try to process everything even if only one field is filled in.