How to get the Max value SQLite Android

How to get the Max value SQLite Android - android

Trying to get the maximum id in my TABLE_GOALS
public String getLatestGoal(){
SQLiteDatabase db=dbhandler.getWritableDatabase();
//columns
Cursor cursor=db.query(MyDBHandler.TABLE_GOALS, null, "SELECT MAX("+MyDBHandler.COLUMN_ID+"))", null, null, null, null);
StringBuffer buffer = new StringBuffer();
while(cursor.moveToNext()){
int index1=cursor.getColumnIndex(MyDBHandler.COLUMN_ID);
String max_id=cursor.getString(index1);
buffer.append(max_id);
}
return buffer.toString();
}
I can't get the maximum value and i don't know why. Sorry, newbie here in Android.

public int getMaxid(){
String selectQuery = "SELECT max(id) as id FROM customerentries";
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
cursor.moveToFirst();
int maxid = cursor.getInt(cursor.getColumnIndex("id"));
return maxid;
}

public String getLatestGoal(){
SQLiteDatabase db=dbhandler.getWritableDatabase();
Cursor c = db.query(MyDBHandler.TABLE_GOALS, new String[]{"MAX("+MyDBHandler.COLUMN_ID+")"}, null, null, null, null, null);
if(c.getCount()>0){
c.moveToFirst();
String max_id=c.getString(0);
buffer.append(max_id);
}
c.close();
db.close();
return buffer.toString();
}

Related

Cursor always returns null - SQLite

I tried this query and the cursor alway return to NULL, in the table "members" exist 1 record, Thank you.
sql = "SELECT nick, pass FROM miembros LIMIT 1";
cursor = write.rawQuery(sql, null);
if (cursor != null){
if(cursor.moveToFirst()) {
nickDB = cursor.getString(0);
passDB = cursor.getString(1);
resp[0] = nickDB;
resp[1] = passDB;
}
// Cierra el cursor
if(!cursor.isClosed()) cursor.close();
}else{
Log.e("CURSOR","CURSOR NULL");
}
return resp;
}

this is working code. compare and try. Change stuff as needed
public void getItem() {
String selectQuery;
SQLiteDatabase db;
String myPath = DATABASE_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
selectQuery = "SELECT * FROM TABLE";
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
cursor.getInt(cursor.getColumnIndex("id"));
while (cursor.moveToNext()) {
cursor.getInt(cursor.getColumnIndex("id"));
}
}
}

Sqlite query for multiple result

i want to query for data in sqlite, but in the case where 2item have the same name.. still it return only result... what should i add in this code?
public String getItemNameRbPrice(long lprice) throws SQLException{
String[] column = new String[]{Pro_ID, Pro_Name, Pro_Price, Pro_Description, Pro_Date};
Cursor c = ourDatabase.query(TABLE_NAME, column, Pro_Price + "=" + lprice, null, null, null, null);
if(c != null){
c.moveToFirst();
String name = c.getString(1);
Log.v(name,name + ("zz"));
return name;
}
return null;
}

Try sending List<String>
public List<String> getItemNameRbPrice(long lprice) throws SQLException{
String[] column = new String[]{Pro_ID, Pro_Name, Pro_Price, Pro_Description, Pro_Date};
Cursor c = ourDatabase.query(TABLE_NAME, column, Pro_Price + "=" + lprice, null, null, null, null);
List<String> lst = new ArrayList<String>();
if (cursor.moveToFirst()) {
do {
String name = c.getString(1);
lst.add(name);
Log.v(name,name + ("zz"));
} while (cursor.moveToNext());
}
return lst;
}

Get data from sqlite database

I have an activity and want to get data from my sqlite database. It works, but my activity only retrieves the last row and not the whole column. What can i do to get the whole column?
This is the code in my database:
public String getName() {
String[] columns = new String[]{ KEY_ROWID, KEY_NAME };
Cursor c = db.query(NAME_TABLE, columns, null, null, null, null, null);
c.moveToFirst();
while(!c.isAfterLast()) {
String name = c.getString(c.getColumnIndex(KEY_NAME));
c.moveToNext();
}
c.close();
return name;
}
This is the code in my activities to contact the database:
Database getdata = new Database(this);
getdata.open();
String data = getdata.getName();
getdata.close();

use cursor.moveToFirst() method example given below
if (cursor.moveToFirst()) {
do {
list.add(cursor.getString(0));
list.add(cursor.getString(1));
list.add(cursor.getString(2));
list.add(cursor.getString(3));
list.add(cursor.getString(4));
list.add(cursor.getString(5));
list.add(cursor.getString(6));
} while (cursor.moveToNext());
}

See, As I said, Without seeing code I m helpless.. And after seeing your code..
You are returning only single String from that function getName() instead it return String[].
Note: this is only pseudo code.. Actual may be different..
public String[] getName() {
int i=0;
String[] columns = new String[]{ KEY_ROWID, KEY_NAME };
Cursor c = db.query(NAME_TABLE, columns, null, null, null, null, null);
String name[] = new String[c.getCount()];
c.moveToFirst();
while(!c.isAfterLast()) {
name[i] = c.getString(c.getColumnIndex(KEY_NAME));
c.moveToNext();
i++;
}
c.close();
return name;
}
And this one,
Database getdata = new Database(this);
getdata.open();
String data[] = getdata.getName();
getdata.close();

Update your code...
public String[] getName() {
String[] columns = new String[]{ KEY_ROWID, KEY_NAME };
int i=0;
Cursor c = db.query(NAME_TABLE, columns, null, null, null, null, null);
c.moveToFirst();
String[] names = new String[c.getCount()];
while(!c.isAfterLast()) {
String name = c.getString(c.getColumnIndex(KEY_NAME));
names[i]=name;
c.moveToNext();
i++;
}
c.close();
return names;
}
Database getdata = new Database(this);
getdata.open();
String[] data = getdata.getName();
getdata.close();

How do I order my SQLITE database in descending order, for an android app?

What is the most efficient method of showing my data in descending order?
public String getRank() {
String[] rank = new String[]{ KEY_ROWID };
Cursor c = scoreDb.query(DATABASE_TABLE, rank, null, null, null, null, null); //reading information from db.
String rankResult = "";
int iRow = c.getColumnIndex(KEY_ROWID); //Cursor looking for column setting equal to these ints.
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
//Move to first row - where cursor starts and moves to next row as long it is not after last row.
rankResult = rankResult + c.getString(iRow) + "\n";
//Returning value of row that it is currently on.
}
return rankResult; //returning result
}
public String getName() {
String[] name = new String[]{ KEY_NAME };
Cursor c = scoreDb.query(DATABASE_TABLE, name, null, null, null, null, null); //reading information from db.
String nameResult = "";
int iRow1 = c.getColumnIndex(KEY_NAME); //Cursor looking for column setting equal to these ints.
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
//Move to first row - where cursor starts and moves to next row as long it is not after last row.
nameResult = nameResult + c.getString(iRow1) + "\n";
//Returning value of row that it is currently on.
}
return nameResult; //returning result
}
public String getScore() {
String[] score = new String[]{ KEY_SCORE };
Cursor c = scoreDb.query(DATABASE_TABLE, score, null, null, null,null, null); //reading information from db.
String scoreResult = "";
int iRow2 = c.getColumnIndex(KEY_SCORE); //Cursor looking for column setting equal to these ints.
for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
//Move to first row - where cursor starts and moves to next row as long it is not after last row.
scoreResult = scoreResult + c.getString(iRow2) + "\n";
//Returning value of row that it is currently on.
}
return scoreResult; //returning result
}

Query has two syntax, the syntax you are using, last column represents orderBy, you just need to specify on what column you want to do orderBy +"ASC" (or) orderBy +"DESC"
Cursor c = scoreDb.query(DATABASE_TABLE, rank, null, null, null, null, yourColumn+" DESC");
Refer this documentation to understand more about query() method.

return database.rawQuery("SELECT * FROM " + DbHandler.TABLE_ORDER_DETAIL +
" ORDER BY "+DbHandler.KEY_ORDER_CREATED_AT + " DESC"
, new String[] {});

Cursor c = scoreDb.query(Table_Name, score, null, null, null, null, Column+" DESC");
Try this

According to docs:
public Cursor query (String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy, String limit);
and your ORDER BY param means:
How to order the rows, formatted as an SQL ORDER BY clause
(excluding the ORDER BY itself). Passing null will use the default
sort order, which may be unordered.
So, your query will be:
Cursor cursor = db.query(TABLE_NAME, null, null,
null, null, null, KEY_ITEM + " DESC", null);

public List getExpensesList(){
SQLiteDatabase db = this.getWritableDatabase();
List<String> expenses_list = new ArrayList<String>();
String selectQuery = "SELECT * FROM " + TABLE_NAME ;
Cursor cursor = db.rawQuery(selectQuery, null);
try{
if (cursor.moveToLast()) {
do{
String info = cursor.getString(cursor.getColumnIndex(KEY_DESCRIPTION));
expenses_list.add(info);
}while (cursor.moveToPrevious());
}
}finally{
cursor.close();
}
return expenses_list;
}
This is my way of reading the record from database for list view in descending order. Move the cursor to last and move to previous record after each record is fetched. Hope this helps~

Cursor c = myDB.rawQuery("SELECT distinct p_name,p_price FROM products order by Id desc",new String[]{});
this works for me!!!

you can do it with this
Cursor cursor = database.query(
TABLE_NAME,
YOUR_COLUMNS, null, null, null, null, COLUMN_INTEREST+" DESC");

SQLite ORDER BY clause is used to sort the data in an ascending or descending order, based on one or more columns.
Cursor c = scoreDb.query(DATABASE_TABLE, rank, null, null, null, null, yourColumn+" DESC");
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(
TABLE_NAME,
rank,
null,
null,
null,
null,
COLUMN + " DESC",
null);

We have one more option to do order by
public Cursor getlistbyrank(String rank) {
try {
//This can be used
return db.`query("tablename", null, null, null, null, null, rank +"DESC",null );
OR
return db.rawQuery("SELECT * FROM table order by rank", null);
} catch (SQLException sqle) {
Log.e("Exception on query:-", "" + sqle.getMessage());
return null;
}
}
You can use this two method for order

This a terrible thing! It costs my a few hours!
this is my table rows :
private String USER_ID = "user_id";
private String REMEMBER_UN = "remember_un";
private String REMEMBER_PWD = "remember_pwd";
private String HEAD_URL = "head_url";
private String USER_NAME = "user_name";
private String USER_PPU = "user_ppu";
private String CURRENT_TIME = "current_time";
Cursor c = db.rawQuery("SELECT * FROM " + TABLE +" ORDER BY " + CURRENT_TIME + " DESC",null);
Every time when I update the table , I will update the CURRENT_TIME for sort.
But I found that it is not work.The result is not sorted what I want.
Finally, I found that, the column "current_time" is the default row of sqlite.
The solution is, rename the column "cur_time" instead of "current_time".

About efficient method. You can use CursorLoader. For example I included my action. And you must implement ContentProvider for your data base. https://developer.android.com/reference/android/content/ContentProvider.html
If you implement this, you will call you data base very efficient.
public class LoadEntitiesActionImp implements LoaderManager.LoaderCallbacks<Cursor> {
public interface OnLoadEntities {
void onSuccessLoadEntities(List<Entities> entitiesList);
}
private OnLoadEntities onLoadEntities;
private final Context context;
private final LoaderManager loaderManager;
public LoadEntitiesActionImp(Context context, LoaderManager loaderManager) {
this.context = context;
this.loaderManager = loaderManager;
}
public void setCallback(OnLoadEntities onLoadEntities) {
this.onLoadEntities = onLoadEntities;
}
public void loadEntities() {
loaderManager.initLoader(LOADER_ID, null, this);
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
return new CursorLoader(context, YOUR_URI, null, YOUR_SELECTION, YOUR_ARGUMENTS_FOR_SELECTION, YOUR_SORT_ORDER);
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
}

Delete all contacts in a group

I'm trying to delete all contacts from a defined group but I don't know how to do a join from the contact table and group table (if it's possible).
ContentResolver cr = getContentResolver();
String where = ContactsContract.Groups.TITLE + " =='LolGroup'";
Cursor cursor = cr.query(
ContactsContract.Contacts.CONTENT_URI, null, where, null, null);
while (cursor.moveToNext()) {
String lookupKey = cursor.getString(
cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
Uri uri = Uri.withAppendedPath(
ContactsContract.Contacts.CONTENT_LOOKUP_URI, lookupKey);
cr.delete(uri, null, null);
}
Of course it gives me an error because there is no "title" in the contacts group, but if I do a join with the ID I should get what i want.
Any idea how to do that join?

It looks strange because ContactsContract.Contacts does not have ContactsContract.Groups.TITLE column. So I think that you can get group id with the group title you want and then search contacts with the group id. The idea might go like following:
public String getGroupIdByTitle(String groupTitle){
try {
cursor = mContentResolver.query(
ContactsContract.Groups.CONTENT_URI,
new String[] {Groups._ID},
Groups.TITLE + "=?",
new String[]{groupTitle},
null);
while (cursor.moveToNext()){
return cursor.getString(cursor.getColumnIndex(0);
}
} finally {
if (cursor!=null) cursor.close();
}
return "";
}
public String getGroupIdOfContact(String lookupKey) {
String where = String.format("%s=? AND %s=?", Data.LOOKUP_KEY, Data.MIMETYPE);
String[] whereArgs = {lookupKey, GroupMembership.CONTENT_ITEM_TYPE};
String groupRowId = "";
Cursor cursor = mContentResolver.query(
Data.CONTENT_URI,
new String[]{GroupMembership.GROUP_ROW_ID},
where, whereArgs, null);
try {
if (cursor.moveToNext()) {
return cursor.getString(cursor.getColumnIndex(GroupMembership.GROUP_ROW_ID));
}
} finally {
if (cursor!=null) cursor.close();
}
return "";
}
public void deleteContactByGroupTitle(String groupTitle) {
String targetGroupId = getGroupIdByTitle(groupTitle);
Cursor cursor = null;
try {
cursor = mContentResolver.query(Contacts.CONTENT_URI, null, null, null, null);
while (cursor.moveToNext()){
String lookupKey = cursor.getString(cursor.getColumnIndex(Contacts.LOOKUP_KEY));
String groupId = getGroupIdOfContact(lookupKey);
if (targetGroupId.equals(groupId)){
//TODO. delete this contact
}
}
} finally {
if (cursor!=null) cursor.close();
}
}
The above code has not tested but I think that basic idea would be same.

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

How to get the Max value SQLite Android - android

public int getMaxid(){ String selectQuery = "SELECT max(id) as id FROM customerentries"; SQLiteDatabase database = this.getWritableDatabase(); Cursor cursor = database.rawQuery(selectQuery, null); cursor.moveToFirst(); int maxid = cursor.getInt(cursor.getColumnIndex("id")); return maxid; }

Related

Cursor always returns null - SQLite

Sqlite query for multiple result

Get data from sqlite database

How do I order my SQLITE database in descending order, for an android app?

Delete all contacts in a group

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