Develop Reference

Sql query page refresh

Experts,
As-Is
I am having application in which textview is displaying the database table count.Which keep change upon inserting the data in to the database table
And issue is changed data is appearing whenever i closed and reopen again only.
To-Be
Textview should show the count the moment data is inserted in to the table. Like auto refresh something like that. Could you assist.
my code is
String strData1 = "";
Cursor c = dbhndlr.getAllEntries();
if (c!= null) {
if (c.moveToFirst()) {
do {
strData1 += c.getString(0);
} while (c.moveToNext());
}
}
tex.setText(strData1);
String strData2 = "";
Cursor c1 = dbhndlr.getAllEntries1();
if (c1!= null) {
if (c1.moveToFirst()) {
do {
strData2 += c1.getString(0);
} while (c1.moveToNext());
}
}
tex1.setText(strData2);
DB
public Cursor getAllEntries(){
String selectQuery = "SELECT count (*) FROM " + TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cur = db.rawQuery(selectQuery, null);
return cur;
}
public Cursor getAllEntries1(){
String selectQuery = "SELECT count (*) FROM " + TABLE_LABELS2;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cur1 = db.rawQuery(selectQuery, null);
return cur1;
}
public List<String> getAllLabels1(){
List<String> labels = new ArrayList<String>();
// Select All Query
String selectQuery = "SELECT count (*) FROM " + TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor1 = db.rawQuery(selectQuery, null);
final ArrayList<String> row1 = new ArrayList<String>();
// looping through all rows and adding to list
if (cursor1.moveToFirst()) {
do {
labels.add(cursor1.getString(1));
} while (cursor1.moveToNext());
}
// closing connection
cursor1.close();
db.close();
// returning lables
return labels;
}

SQLite Query to Get Column Data

Using following query to get column data:
public String getR(String str) {
String strR = "SELECT col_no FROM tracking where col_id = '"+str+"' ORDER BY col_no DESC LIMIT 1";
return strR;
}
In Activity, I am trying to read returned strR :
String string = mydb.getR("1400");
Toast.makeText(SyncAll.this, string, Toast.LENGTH_SHORT).show();
But in Toast, I am getting my Select query itself instead of Record, like this:
SELECT col_no FROM tracking where col_id = '1400' ORDER BY col_no DESC LIMIT 1
May I know ! Where I am doing mistake ?

I tried the same way suggested by prosper k above, and finally got the solution:
public String getR(String str) {
String strR = "SELECT col_no FROM tracking where col_id = '"+str+"' ORDER BY col_no DESC LIMIT 1";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(strR, null);
if (cursor != null)
cursor.moveToFirst();
strR = cursor.getString(0);
return strR;
}

You're calling the function getR, which is returning the string value strR.
I'm assuming that mydb is an extended object from class SQLiteOpenHelper, and that you have followed the documentation here https://developer.android.com/training/basics/data-storage/databases.html then you'll have to execute the query like:
Cursor cursor = null;
try {
SQLiteDatabase db = this.getWritableDatabase();
synchronized(this) {
cursor = db.rawQuery(query, null);
if (cursor.moveToFirst()) {
col_no = cursor.getInt(0);
}
}
} finally {
if (null != cursor)
cursor.close();
}
return col_no;

How to correctly write big CRUD sqlite android app

I'm writing an app that manipulates with database consists of 3 tables. I created this database from json file using models (Worker model, specialty model) with getters and setters. Now I want to get specific info from this database. I'v already made it but my code is pretty silly. What I need is to change the architecture of my app but I don't know how exactly it should looks like.
This is the examples of my methods, and they are pretty week
This is how I add info into database. I like it, I think it's correct:
public void addWorker(Worker worker){
List<Specialty> specialty;
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
//fixind names
String f_name = fixName(worker.getF_name());
String l_name = fixName(worker.getL_name());
String birthday = fixDate(worker.getBirthday());
values.put(KEY_F_NAME, f_name);
values.put(KEY_L_NAME, l_name);
values.put(KEY_BIRTHDAY, birthday);
values.put(KEY_AVATR_URL, worker.getAvart_url());
specialty = worker.getSpecialty();
long worker_id = db.insert(TABLE_WORKERS,null,values);
//add unique specialty
for (Specialty spec: specialty){
createRelations(worker_id, spec.getSpecialty_id());
if (getCount(spec.getSpecialty_id()) == 0){
addSpecialty(spec);
}
}
}
And this is how I take info from database:
public String[] getFullInfo(String worker_name){
String selectQuery = "HUGE QUERY HERE "where workers.f_name =?";
Log.e(LOG_TAG, selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery, new String [] {worker_name});
String[] details = new String[5];
c.moveToFirst();
while (c.isAfterLast() == false){
details[0] = c.getString(c.getColumnIndex(KEY_F_NAME));
details[1] = c.getString(c.getColumnIndex(KEY_L_NAME));
details[2] = c.getString(c.getColumnIndex(KEY_BIRTHDAY));
details[3] = c.getString(c.getColumnIndex("age"));
details[4] = c.getString(c.getColumnIndex(KEY_SPEC_NAME));
c.moveToNext();
}
return details;
}
This is my another query and it has different return type:
public List<Map<String ,String>> getWorkerListBySpec(String spec_name){
String selectQuery = "HUGE QUERY HERE
"where specialty.spec_name=?";
Log.e(LOG_TAG, selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery, new String [] {spec_name});
//making list of workers
List<Map<String ,String>> data = new ArrayList<Map<String,String>>();
c.moveToFirst();
while (c.isAfterLast() == false){
Map<String,String> datum = new HashMap<String,String>(2);
datum.put(KEY_F_NAME, c.getString(c.getColumnIndex(KEY_F_NAME)));
datum.put(KEY_L_NAME, c.getString(c.getColumnIndex(KEY_L_NAME)));
datum.put(KEY_BIRTHDAY, c.getString(c.getColumnIndex(KEY_BIRTHDAY)));
data.add(datum);
c.moveToNext();
}
return data;
}
and the third one, which also have different return type:
public List<String> getAllSpecs_Names(){
List<String> spec_names = new ArrayList<String>();
String selectQuery = "select * from " + TABLE_SPECIALTY;
Log.e(LOG_TAG, selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery, null);
if (c.moveToFirst()){
do{
spec_names.add(c.getString(c.getColumnIndex(KEY_SPEC_NAME)));
}while (c.moveToNext());
}
return spec_names;
}
I know, that this is all wrong.
Please tell me how I should make all my queries.
It will be good if you give me the link to check how the app should look like

instead of returning a List or Map, you should better return a own CursorWrapper
so you could could look like this:
public WorkerCursor getWorkerListBySpec(String spec_name){
String selectQuery = "HUGE QUERY HERE
"where specialty.spec_name=?";
Log.e(LOG_TAG, selectQuery);
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery(selectQuery, new String [] {spec_name});
return new WorkerCursor(cursor);
}
public static class WorkerCursor extends CursorWrapper {
/**
* Creates a cursor wrapper.
*
* #param cursor The underlying cursor to wrap.
*/
public WorkerCursor(Cursor cursor) {
super(cursor);
}
public Worker getWorker() {
return getWorkerAtCursor();
}
public Worker getWorker(int position) {
if (moveToPosition(position)) {
return getWorkerCursor();
} else {
return null;
}
}
private Worker getWorkerAtCursor() {
if (isBeforeFirst() || isAfterLast()) {
return null;
}
worker worker = new Worker();
worker.name = c.getString(c.getColumnIndex(KEY_F_NAME));
....
return worker;
}
}
and the same for your List, just with a other CursorWrapper
and don't forget to close the CursorWrapper, when it's no more needed, like in onDestroy of Activity and so

how to get all IDs from a sqlite database

I have a database manager class where i build a table that has two columns. the first column being an integer, and i am trying to write a method that will return all values in that column as a list:
public List<Integer> getAllStyleIDs(){
List<Integer> results = null;
SQLiteDatabase db = this.getReadableDatabase();
// Select All Query
String selectQuery = "select * from " + DBConstants.allStyles;
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
results.add(cursor.getInt(0));
} while (cursor.moveToNext());
}
cursor.close();
db.close();
return results;
}
but i am getting a null point exception
any ideas?

Your list results is null, then you attempt to add to it. Try this:
List<Integer> results = new ArrayList<Integer>();

First thing: the list hasn't been initialized.
Second thing: using raw queries is not recommended:
Try something like this:
List<Integer> results = new ArrayList<Integer>();
this.database = this.getReadableDatabase();
String [] columns = {_ID}; // name of the column
Cursor cursor = this.database.query(COURSES_TABLE, columns, null, null, null, null, null);
int iId = cursor.getColumnIndex(_ID);
for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext())
{
Integer rowId = cursor.getInt(iName);
results.add(rowId);
}
cursor.close();
this.database.close();
return results;

Get all rows from SQLite

I have been trying to get all rows from the SQLite database. But I got only last row from the following codes.
FileChooser class:
public ArrayList<String> readFileFromSQLite() {
fileName = new ArrayList<String>();
fileSQLiteAdapter = new FileSQLiteAdapter(FileChooser.this);
fileSQLiteAdapter.openToRead();
cursor = fileSQLiteAdapter.queueAll();
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
fileName.add(cursor.getString(cursor.getColumnIndex(FileSQLiteAdapter.KEY_CONTENT1)));
} while (cursor.moveToNext());
}
cursor.close();
}
fileSQLiteAdapter.close();
return fileName;
}
FileSQLiteAdapter class:
public Cursor queueAll() {
String[] columns = new String[] { KEY_ID, KEY_CONTENT1 };
Cursor cursor = sqLiteDatabase.query(MYDATABASE_TABLE, columns, null,
null, null, null, null);
return cursor;
}
Please tell me where is my incorrect. Appreciate.

try:
Cursor cursor = db.rawQuery("select * from table",null);
AND for List<String>:
if (cursor.moveToFirst()) {
while (!cursor.isAfterLast()) {
String name = cursor.getString(cursor.getColumnIndex(countyname));
list.add(name);
cursor.moveToNext();
}
}

Using Android's built in method
If you want every column and every row, then just pass in null for the SQLiteDatabase column and selection parameters.
Cursor cursor = db.query(TABLE_NAME, null, null, null, null, null, null, null);
More details
The other answers use rawQuery, but you can use Android's built in SQLiteDatabase. The documentation for query says that you can just pass in null to the selection parameter to get all the rows.
selection Passing null will return all rows for the given table.
And while you can also pass in null for the column parameter to get all of the columns (as in the one-liner above), it is better to only return the columns that you need. The documentation says
columns Passing null will return all columns, which is discouraged to prevent reading data from storage that isn't going to be used.
Example
SQLiteDatabase db = mHelper.getReadableDatabase();
String[] columns = {
MyDatabaseHelper.COLUMN_1,
MyDatabaseHelper.COLUMN_2,
MyDatabaseHelper.COLUMN_3};
String selection = null; // this will select all rows
Cursor cursor = db.query(MyDatabaseHelper.MY_TABLE, columns, selection,
null, null, null, null, null);

This is almost the same solution as the others, but I thought it might be good to look at different ways of achieving the same result and explain a little bit:
Probably you have the table name String variable initialized at the time you called the DBHandler so it would be something like;
private static final String MYDATABASE_TABLE = "anyTableName";
Then, wherever you are trying to retrieve all table rows;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("select * from " + MYDATABASE_TABLE, null);
List<String> fileName = new ArrayList<>();
if (cursor.moveToFirst()){
fileName.add(cursor.getString(cursor.getColumnIndex(COLUMN_NAME)));
while(cursor.moveToNext()){
fileName.add(cursor.getString(cursor.getColumnIndex(COLUMN_NAME)));
}
}
cursor.close();
db.close();
Honestly, there are many ways about doing this,

I have been looking into the same problem! I think your problem is related to where you identify the variable that you use to populate the ArrayList that you return. If you define it inside the loop, then it will always reference the last row in the table in the database. In order to avoid this, you have to identify it outside the loop:
String name;
if (cursor.moveToFirst()) {
while (cursor.isAfterLast() == false) {
name = cursor.getString(cursor
.getColumnIndex(countyname));
list.add(name);
cursor.moveToNext();
}
}

Update queueAll() method as below:
public Cursor queueAll() {
String selectQuery = "SELECT * FROM " + MYDATABASE_TABLE;
Cursor cursor = sqLiteDatabase.rawQuery(selectQuery, null);
return cursor;
}
Update readFileFromSQLite() method as below:
public ArrayList<String> readFileFromSQLite() {
fileName = new ArrayList<String>();
fileSQLiteAdapter = new FileSQLiteAdapter(FileChooser.this);
fileSQLiteAdapter.openToRead();
cursor = fileSQLiteAdapter.queueAll();
if (cursor != null) {
if (cursor.moveToFirst()) {
do
{
String name = cursor.getString(cursor.getColumnIndex(FileSQLiteAdapter.KEY_CONTENT1));
fileName.add(name);
} while (cursor.moveToNext());
}
cursor.close();
}
fileSQLiteAdapter.close();
return fileName;
}

Cursor cursor = myDb.viewData();
if (cursor.moveToFirst()){
do {
String itemname=cursor.getString(cursor.getColumnIndex(myDb.col_2));
String price=cursor.getString(cursor.getColumnIndex(myDb.col_3));
String quantity=cursor.getString(cursor.getColumnIndex(myDb.col_4));
String table_no=cursor.getString(cursor.getColumnIndex(myDb.col_5));
}while (cursor.moveToNext());
}
cursor.requery();

public List<String> getAllData(String email)
{
db = this.getReadableDatabase();
String[] projection={email};
List<String> list=new ArrayList<>();
Cursor cursor = db.query(TABLE_USER, //Table to query
null, //columns to return
"user_email=?", //columns for the WHERE clause
projection, //The values for the WHERE clause
null, //group the rows
null, //filter by row groups
null);
// cursor.moveToFirst();
if (cursor.moveToFirst()) {
do {
list.add(cursor.getString(cursor.getColumnIndex("user_id")));
list.add(cursor.getString(cursor.getColumnIndex("user_name")));
list.add(cursor.getString(cursor.getColumnIndex("user_email")));
list.add(cursor.getString(cursor.getColumnIndex("user_password")));
// cursor.moveToNext();
} while (cursor.moveToNext());
}
return list;
}

a concise solution can be used for accessing the cursor rows.
while(cursor.isAfterLast)
{
cursor.getString(0)
cursor.getString(1)
}
These records can be manipulated with a loop