Develop Reference

Android studio SQL - How to return data in a string array

I have an SQL method here. I would like to return the data in a String[] array.
How do I do that exactly?
Thank you!
public String[] getLikedSongs() {
SQLiteDatabase db = this.getReadableDatabase();
String[] LikeSong;
Cursor cursor = db.rawQuery(" SELECT " + COL_4 + " FROM " + Table_Name + " WHERE " + COL_4 + " IS NOT NULL", null);
while (cursor.moveToNext()) {
String note = cursor.getString(0);
}
cursor.close();
db.close();
return LikeSong;
}

You must define the array's length and this can be done only after the Cursor fetches all the rows. Then set its length to the nimber of rows of the Cursor.
Then inside the while loop set the items of the array:
public String[] getLikedSongs() {
String[] LikeSong = null;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT " + COL_4 + " FROM " + Table_Name + " WHERE " + COL_4 + " IS NOT NULL", null);
if (cursor.getCount() > 0) {
LikeSong = new String[cursor.getCount()];
int i = 0;
while (cursor.moveToNext()) {
LikeSong[i] = cursor.getString(0);
i++;
}
}
cursor.close();
db.close();
return LikeSong;
}

How to get other column with onItemClickListener in ListView

I am working on a Shopping list where you can click on the item in the ListView and a dialog comes up. There you can modify the product name. It works fine, but now i am trying to add details.
Adding to database already works. It is in the third column but now I cant get it out with the onItemClickListener.
Get Data from the second column works fine, so the the product is working fine with ItemOnClick.
I already tried a couple of codes but didnt find a solution.
OnItemClick:
lvProducts.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
try {
//DB*********************************
String name = parent.getItemAtPosition(position).toString();
Log.d(TAG, "onItemClick: You Clicked on " + name);
Cursor data = myDB.getItemID(name);
int itemID = -1;
while (data.moveToNext()){
itemID = data.getInt(0);
}
if (itemID > -1){
Log.d(TAG, "onItemClick: The ID is " + itemID);
Intent editScreenIntent = new Intent();
editScreenIntent.putExtra("id",itemID);
editScreenIntent.putExtra("name",name);
selectedID = editScreenIntent.getIntExtra("id",-1);
selectedName = editScreenIntent.getStringExtra("name");
}
showInputBox(arrayList.get(position), position);
} catch (Exception e) {
Toast.makeText(ShoppingActivity.this, "Error#666", Toast.LENGTH_SHORT).show();
}
}
});
DatabaseHelper:
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String TABLE_NAME = "myList_data";
public static final String COL1 = "ID";
public static final String COL2 = "ITEM1";
public static final String COL3 = "ITEM2";
public DatabaseHelper(Context context){
super(context, TABLE_NAME, null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
String createTable = "CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " + COL2 + " TEXT, " + COL3 + " TEXT )";
db.execSQL(createTable);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+ TABLE_NAME);
onCreate(db);
}
public boolean addData(String item, String detail){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL2,item);
contentValues.put(COL3, detail);
long result = db.insert(TABLE_NAME,null,contentValues);
if (result == -1){
return false;
}else {
return true;
}
}
public Cursor getData(){
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT * FROM " + TABLE_NAME;
Cursor data = db.rawQuery(query, null);
return data;
}
public Cursor getItemID(String name){
SQLiteDatabase db = this.getWritableDatabase();
//String query = "SELECT "+ COL1 + " FROM " + TABLE_NAME + " WHERE " + COL2 + " = '" + name + "'";
Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME,null);
//Cursor data = db.rawQuery(query, null);
return data;
}
/**
* Updates the name field
* #param newName
* #param id
* #param oldName
*/
public void updateName(String newName,int id,String oldName){
SQLiteDatabase db = this.getWritableDatabase();
String query = "UPDATE " + TABLE_NAME + " SET " + COL2 + " = '" + newName + "' WHERE " + COL1 + " = '" + id + "'" + " AND " + COL2 + " = '" + oldName + "'";
db.execSQL(query);
}
public void deleteName(int id, String name){
SQLiteDatabase db = this.getWritableDatabase();
String query = "DELETE FROM " + TABLE_NAME + " WHERE " + COL1 + " = '" + id + "'" + " AND " + COL2 + " = '" + name + "'";
db.execSQL(query);
}
public void deleteAll(){
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_NAME,null,null);
String query =("DELETE FROM " + TABLE_NAME);
db.execSQL(query);
}
}

Try :-
int itemID = -1;
String item3 = ""; //<<<<<<<<<< ADDED
while (data.moveToNext()){
itemID = data.getInt(0);
item3 = data.getString(data.getColumnIndex(DatabaseHelper.COL3)); //<<<<<<<<<< ADDED
}
Note using getColumnIndex and the column name is more flexible and less prone to mis-calculation of offsets. You may wish to consider changing itemID = data.getInt(0); to itemID = data.getInt(data.getColumnIndex(DatabaseHelper.COL1));
Your getItemId method will, as it stands get all rows not just the row that has the name. You may wish to change from :-
public Cursor getItemID(String name){
SQLiteDatabase db = this.getWritableDatabase();
//String query = "SELECT "+ COL1 + " FROM " + TABLE_NAME + " WHERE " + COL2 + " = '" + name + "'";
Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME,null);
//Cursor data = db.rawQuery(query, null);
return data;
}
to :-
public Cursor getItemID(String name){
SQLiteDatabase db = this.getWritableDatabase();
return db.query(TABLE_NAME,null,COL2+"=?",new String[]{name},null,null,null);
}
Note the above is in-principle code. It has not been tested or run and may therefore have some errors.

How to send parameter to where clause in a Sqlite query

I'm trying to get a single row from database.But it is not generated query. The questions marks still seems. What am i missing ?
public static User getSingleUser(String email,String password)
{
User user = new User();
SQLiteDatabase db = DatabaseManager.getInstance().openDatabase();
String selectQuery = " SELECT * FROM " + User.TABLE + " WHERE "
+ User.KEY_EMAIL + "=?"+ " AND " + User.KEY_PASSWORD
+ "=?" ;
Cursor cursor = db.rawQuery(selectQuery,new String[]{email,password},null);
if (cursor.moveToFirst()) {
do {
user.setId(cursor.getInt(cursor.getColumnIndex("UserId")));
user.setFirstname(cursor.getString(cursor.getColumnIndex("Firstname")));
user.setLastname(cursor.getString(cursor.getColumnIndex("Lastname")));
user.setEmail(cursor.getString(cursor.getColumnIndex("Email")));
user.setPassword(cursor.getString(cursor.getColumnIndex("Password")));
user.setIsActive(cursor.getInt(cursor.getColumnIndex("IsActive")));
} while (cursor.moveToNext());
}
return user;
}
}

Try this,
String selection = User.KEY_EMAIL + "=?"+ " AND " + User.KEY_PASSWORD + "=?";
String[] selectionArgs = new String[]{ email, password };
Cursor cursor = db.query(User.TABLE, null, selection, selectionArgs, null, null, null);

try to use native android query as below -
Cursor cursor = db.query(User.TABLE, null, User.KEY_EMAIL + "=? and " + User.KEY_PASSWORD + "=?", new String[] {email, password}, null, null, null );

Specific query error - SQLite Android

my problem is with very specific query. My SQLite datbase is only 1 table with 11 entries. It creates just fine, but upon execution of this piece of code it crashes. When I change the query to simply:
SELECT * FROM Items
Then it works fine, but I need more narrow results, therefore I modify with the "WHERE" clause. But then it crashes and the application stops. If I comment out the Cursor... it runs fine.
public int findPictureNumber(String itemtitle) {
String query = "SELECT nr_of_pics FROM Items WHERE ItemTitle = \"" + itemtitle + "\"";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query, null);
...
}
Where is the error? I can't seem to find it even after narrowing it down to those lines of code.
EDIT:
This is a method for adding an item to a database.
public void newItemFuro () {
MyDBHandler dbHandler = new MyDBHandler(this, null, null, 1);
String title = "Furo";
String author = "Fernando Brizio";//í
String category = "Decoracao";//çã
int date = 2012;
String type = "Taca";//ç
String country = "Portugal";
String colour = "Castanho/Cortica";//ç
String material = "Castanho/Cortica";//ç
boolean isFavourite = false;
String imgres = "furoo";
int nr_of_pics = 3;
Item item = new Item(title, author, category, date, type, country, colour, material, isFavourite, imgres, nr_of_pics);
dbHandler.addItem(item);
}
//helper for types
public static final String VARCHAR_TYPE = " VARCHAR(50)";
public static final String BOOL_TYPE = " BOOLEAN";
public static final String INT_TYPE = " INTEGER";
Here it creates the table:
public void onCreate(SQLiteDatabase db) {
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS +
"("
+ COLUMN_ENTRY_ID + INT_TYPE +" PRIMARY KEY AUTOINCREMENT,"
+ COLUMN_TITLE + VARCHAR_TYPE + ","
+ COLUMN_AUTHOR + VARCHAR_TYPE + ","
+ COLUMN_CATEGORY + VARCHAR_TYPE + ","
+ COLUMN_DATE + INT_TYPE + ","
+ COLUMN_TYPE + VARCHAR_TYPE + ","
+ COLUMN_COUNTRY + VARCHAR_TYPE + ","
+ COLUMN_COLOUR + VARCHAR_TYPE + ","
+ COLUMN_MATERIAL + VARCHAR_TYPE + ","
+ COLUMN_FAVOURITE + BOOL_TYPE + ","
+ COLUMN_IMGRES + VARCHAR_TYPE + ","
+ COLUMN_NUMBER_OF_PICS + INT_TYPE +
")";
db.execSQL(CREATE_ITEMS_TABLE);
}
Adding item:
public void addItem(Item item) {
ContentValues values = new ContentValues();
values.put(COLUMN_TITLE, item.getItemTitle());
values.put(COLUMN_AUTHOR, item.getAuthor());
values.put(COLUMN_CATEGORY, item.getCategory());
values.put(COLUMN_DATE, item.getDate());
values.put(COLUMN_TYPE, item.getType());
values.put(COLUMN_COUNTRY, item.getCountry());
values.put(COLUMN_COLOUR, item.getColour());
values.put(COLUMN_MATERIAL, item.getMaterial());
values.put(COLUMN_FAVOURITE, item.getFavourite());
values.put(COLUMN_IMGRES, item.getImgres());
values.put(COLUMN_NUMBER_OF_PICS, item.getNumberOfPics());
SQLiteDatabase db = this.getWritableDatabase();
db.insert(TABLE_ITEMS, null, values);
db.close();
}
Here full function for searching nr_of_pics:
public int findPictureNumber(String itemtitle) {
String query = "SELECT nr_of_pics FROM Items WHERE ItemTitle = '" + itemtitle + "'";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(query, null);
int PicsNumber=0;
if (cursor.moveToFirst()) {
cursor.moveToFirst();
PicsNumber=Integer.parseInt(cursor.getString(0));
cursor.close();
return PicsNumber;
} else {
//wtf?
}
db.close();
return 0;
}
And the errors say as follows:
(1) table Items has no column named imgres
Error inserting colour=Castanho/Cortiça author=Fernando Brízio
imgres=furo category=Decoração title=Furo type=Taça date=2012
nr_of_pics=3 material=Castanho/Cortiça is_favourite=false
country=Portugal
android.database.sqlite.SQLiteException: table Items has no column named imgres (code 1): , while
compiling: INSERT INTO
Items(colour,author,imgres,category,title,type,date,nr_of_pics,material,is_favourite,country)
VALUES (?,?,?,?,?,?,?,?,?,?,?)

You do not give any exception but I think you have error in your SQL. You need to use ' instead of ".
Change your query as below.
String query = "SELECT nr_of_pics FROM Items WHERE ItemTitle = '" + itemtitle + "'";

It is clear that you don't have any column that named "imgres"!
You should modify your query
"INSERT INTO Items(colour,author,imgres,category,title,type,date,nr_of_pics,material,is_favourite,country)
VALUES (?,?,?,?,?,?,?,?,?,?,?)"

Android SQLLiteDataBase cursor returning 0 rows

For the life of me, I can't get the cursor to return any data. I've verified that their is data in the database and my insertions are working. The official error is:
CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
Top level declarations:
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
this.db = this.DBHelper.getWritableDatabase();
}
My function:
public String getRandomEntry()
{
int rand;
Random random = new Random();
int numEntries = (int)this.getCount();
if(numEntries == 0)
return "ERROR: Database is empty.";
rand = random.nextInt(numEntries);
Cursor cursor = DBHelper.getWritableDatabase().rawQuery(
"SELECT * FROM " + DATABASE_TABLE
+ " WHERE " + COLUMN_A + " = " + 0, null);
Log.i("numEntries", Integer.toString(numEntries));
Log.i("rand", Integer.toString(rand));
Log.i("cursor", Integer.toString(cursor.getCount()));
cursor.moveToFirst();
return cursor.getString(0);
}
I've also tried grabbing the cursor as such:
Cursor cursor = db.rawQuery(
"SELECT * FROM " + DATABASE_TABLE
+ " WHERE " + COLUMN_A + " = " + 0, null);
Please give me your thoughts! Thank you!!

Nothing seems random here at all. It appears that you are looking for column_a with a value of 0 every time.
I would assume that column_a has nothing with a value of 0.

First of all try to query this way:
String args[] = new String[]{"0"};
Cursor cursor = db.rawQuery(
"SELECT * FROM " + DATABASE_TABLE + " WHERE " + COLUMN_A + " = ?", args);
If this not helps check your db with external tool if you query return rows there.