Develop Reference

Inserting or Reading values in an SQLite database doesn't yield any results

Started with SQLite in Android this evening. Practiced all the code from the Google documentation but it's still going wrong and I can't figure out where I'm going wrong. Take a look and see if you can find out any details.
DatabaseHelperContract.java
package com.practice.sqlitepractice;
import android.provider.BaseColumns;
//final class to prevent inheritance
public final class DatabaseHelperContract {
//Create Entry String
public static final String CREATE_ENTRY = "CREATE TABLE " + DatabaseSchema.TABLE_NAME + " (" +
DatabaseSchema._ID + " INTEGER PRIMARY KEY, " + DatabaseSchema.COLUMN_NAME + " TEXT)";
//private constructor to prevent accidental instantiation
private DatabaseHelperContract(){
}
/*Inner class that defines individual table contents*/
public static class DatabaseSchema implements BaseColumns{
public static final String TABLE_NAME = "details";
public static final String COLUMN_NAME = "name";
}
}
DatabaseHelper.class
package com.practice.sqlitepractice;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
class DatabaseHelper extends SQLiteOpenHelper {
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "table.db";
public DatabaseHelper(#Nullable Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL(DatabaseHelperContract.CREATE_ENTRY);
}
#Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
}
MainActivity.java
package com.practice.sqlitepractice;
import androidx.appcompat.app.AppCompatActivity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private EditText nameEditText;
private Button insertButton;
private Button readButton;
private ListView detailsListView;
private DatabaseHelper databaseHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initializeWidgetsMethod();
}
#Override
protected void onDestroy() {
super.onDestroy();
databaseHelper.close();
}
private void insertionMethod(String name) {
//gets the data repository in write mode
SQLiteDatabase sqLiteDatabase = databaseHelper.getWritableDatabase();
//create a new map of values, where the columns are the keys
ContentValues contentValues = new ContentValues();
contentValues.put(DatabaseHelperContract.DatabaseSchema.COLUMN_NAME, name);
try {
long newRowID = sqLiteDatabase.insert(DatabaseHelperContract.DatabaseSchema.TABLE_NAME, null, contentValues);
Toast.makeText(this, "ID for newly created row: " + newRowID, Toast.LENGTH_SHORT).show();
} catch (SQLException exception) {
exception.printStackTrace();
}
}
private void readMethod() {
SQLiteDatabase sqLiteDatabase = databaseHelper.getReadableDatabase();
String[] projection = {DatabaseHelperContract.DatabaseSchema.COLUMN_NAME};
try {
Cursor cursor = sqLiteDatabase.query(
DatabaseHelperContract.DatabaseSchema.TABLE_NAME,
projection,
null,
null,
null,
null,
null);
List<String> itemIDs = new ArrayList<>();
while (cursor.moveToNext()) {
String name = cursor.getString(cursor.getColumnIndex(DatabaseHelperContract.DatabaseSchema.COLUMN_NAME));
itemIDs.add(name);
}
cursor.close();
displayMethod(itemIDs);
} catch (SQLiteException exception) {
exception.printStackTrace();
}
}
private void displayMethod(List<String> list) {
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, R.id.details_list_view, list);
detailsListView.setAdapter(arrayAdapter);
}
#Override
public void onClick(View view) {
if (view == readButton) {
readMethod();
}
if (view == insertButton) {
String name = nameEditText.getText().toString();
insertionMethod(name);
}
}
private void initializeWidgetsMethod() {
nameEditText = findViewById(R.id.name_edit_text);
insertButton = findViewById(R.id.insert_button);
readButton = findViewById(R.id.read_button);
detailsListView = findViewById(R.id.details_list_view);
databaseHelper = new DatabaseHelper(getApplicationContext());
}
}
Note: I know that database transactions are expensive and should always be performed asynchronously. This code is just for practice and I will be performing all those at a later stage.

The problem with your code is the way that you initialize the ArrayAdapter in displayMethod().
The 3d argument of this definition:
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(
this,
android.R.layout.simple_list_item_1,
R.id.details_list_view,
list
);
is R.id.details_list_view which is the ListView resource id, while you should have used a TextView resource id but only if you have created one to use inside the ListView.
Did you create such a TextView?
If not then you can use the default TextView, by not passing this argument.
So change the code to this:
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(
this,
android.R.layout.simple_list_item_1,
list
);

how to use context in class which implements Screen?

i have a problem to use a database in libGdx, for use this first i create this class:
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DataBaseHelper extends SQLiteOpenHelper {
public DataBaseHelper(Context context, String name,CursorFactory factory, int version)
{
super(context, name, factory, version);
}
#Override
public void onCreate(SQLiteDatabase _db)
{
_db.execSQL(DataBaseClass.DATABASE_RECORD);
}
#Override
public void onUpgrade(SQLiteDatabase _db, int _oldVersion, int _newVersion)
{
Log.w("TaskDBAdapter", "Upgrading from version " +_oldVersion + " to " +_newVersion + ", which will destroy all old data");
onCreate(_db);
}
}
and this class:
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Collections;
public class DataBaseClass {
static final String DATABASE_NAME = "my.database";
static final int DATABASE_VERSION = 1;
public static final int NAME_COLUMN = 1;
static final String DATABASE_RECORD = "create table "+"RECORD"+
"( " + "SCORE text, GAMES_PLAYED text); ";
public SQLiteDatabase db;
private final Context context;
private DataBaseHelper dbHelper;
public DataBaseClass(Context _context) {
context = _context;
dbHelper = new DataBaseHelper(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public DataBaseClass open() throws SQLException {
db = dbHelper.getWritableDatabase();
return this;
}
public void close() {
db.close();
}
public SQLiteDatabase getDatabaseInstance() {
return db;
}
public void updateGamesPlayed(String game) {
ContentValues updatedValues = new ContentValues();
updatedValues.put("GAMES_PLAYED", game);
String where="GAMES_PLAYED = ?";
db.update("RECORD",updatedValues, where, new String[]{game});
}
public void updateBestScore(String score) {
ContentValues updatedValues = new ContentValues();
updatedValues.put("SCORE", score);
String where="SCORE = ?";
db.update("RECORD",updatedValues, where, new String[]{score});
}
}
but when i call the DataBaseClass in my principal class, which implement the interface Screen, i have problem here:
DBClass = new DataBaseClass(CONTEXT);
what is the context in this class? i try to use: "this", "getContext()", getActivity","this.getActivity", etc... but nothing works.
can someone help me?

Context here refers to your current class context you can simply pass this or principal.this

Getting Error when attempting to save to database

I'm a beginner with android studio, so I'm stumbling my way through building my first app. I've come up with and error when attempting to save my data to a database. Whenever I try to save any digits, the app crashes.
Database Java file:
package com.miahollins.basketballfinal;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Created by pumpkin on 6/17/16.
*/
public class DataHandler {
public static final String GAMES = "games_played";
public static final String GAMES2 = "games_started";
public static final String GAMES3 = "points";
public static final String TABLE_NAME = "statstable";
public static final String DATA_BASE_NAME = "mydatabase.sqlite";
public static final int DATABASE_VERSION = 2;
public static final String TABLE_CREATE = "create table statstable (games_played VARCHAR not null, games_started VARCHAR not null, points VARCHAR not null)";
DatabaseHelper dbhelper;
Context ctx;
SQLiteDatabase db;
public DataHandler(Context ctx){
this.ctx = ctx;
dbhelper = new DatabaseHelper(ctx);
}
private static class DatabaseHelper extends SQLiteOpenHelper{
public DatabaseHelper(Context ctx){
super(ctx, DATA_BASE_NAME,null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(TABLE_CREATE);
} catch(SQLException e){
e.printStackTrace();
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS statstable");
onCreate(db);
}
}
public DataHandler open(){
db = dbhelper.getWritableDatabase();
return this;
}
public void close(){
dbhelper.close();
}
public long insertData(String games_played, String games_started, String points){
ContentValues content = new ContentValues();
content.put(GAMES, games_played);
content.put(GAMES2, games_started);
content.put(GAMES3, points);
return db.insertOrThrow(TABLE_NAME, null, content);
}
public Cursor returnData(){
return db.query(TABLE_NAME, new String[]{GAMES, GAMES2, GAMES3},null, null, null, null, null);
}
}
In my logcat I get an error saying that columns cannot be found. Any help is appreciated!

Android SQLite data inserting

I am creating an android application that has two databases. One is offline SQLite database directly on the device and another one on public server that is used for update the offline one.
This is the way I'm inserting data into my SQLite database:
My activity:
package com.empekapp;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
public class Linie extends Activity {
DBAdapter db
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.linie);
openDB();
}
private void openDB(){
db = new DBAdapter(this);
db.open();
db.insertLineRecord("1");
db.insertLineRecord("2");
}
And in my database adapter:
public static final String KEY_LINE_ROWID = "_id";
public static final String KEY_LINE_NAME = "line_name";
public static final int COL_LINE_ROWID = 0;
public static final int COL_LINE_NAME = 1;
public static final String[] ALL_LINE_KEYS = new String[] {KEY_LINE_ROWID, KEY_LINE_NAME};
private static final String TABLE_LINE = "lines";
private static final String TABLE_LINE_CREATE =
"create table if not exists " + TABLE_LINE + "("
+ KEY_LINE_ROWID + " integer primary key autoincrement, "
+ KEY_LINE_NAME + " VARCHAR not null unique);";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter (Context ctx){
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper{
DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(TABLE_LINE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LINE);
}
}
public DBAdapter open(){
db = DBHelper.getWritableDatabase();
return this;
}
public void close(){
DBHelper.close();
}
public void insertLineRecord(String line_name){
db.execSQL("INSERT OR IGNORE INTO " + TABLE_LINE + "('"
+ KEY_LINE_NAME + "') VALUES ('"
+ line_name + "');");
}
Generally this solution is enough for me.. but data is inserted to the table everytime I'm opening that activity to prevent this I set the unique constraint but how to insert data only once, when I'm creating that table to avoid situation like this?

use the data insertion in onCreate of database adapter class as this will be called only once when database created by this you can make it insert only once and no need to unique constaraint as well
Like this:
public void onCreate(SQLiteDatabase db) {
db.execSQL(TABLE_LINE_CREATE);
db.insertLineRecord("1");
db.insertLineRecord("2");
}

How to create a two table in single Database in Android Application?

I have Created a database in Sqllite Android Application and I tried to add two tables in my Database, but I have problem to create that Database. First Table only Created. Can anyBody help me?
package com.android.cdtech;
import java.sql.SQLException;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class saveData {
public static final String KEY_ROWID = "rowid"; public static final String KEY_DATE = "Date";public static final String KEY_NAME = "CustomerName";public static final String KEY_AMOUNT = "Amount";public static final String KEY_BANK = "Banks";
private static final String TAG = "DBAdapter";
public static final String KEY_BUSNAME="BusinessName";public static final String KEY_ADD="Address";public static final String KEY_CPERSON="ContactPerson";;
private static final String DATABASE_NAME = "EXPORTDETAILS";
private static final String DATABASE_TABLE = "Payment";
private static final String DATABASE_TABLE2 = "Customer";
private static final int DATABASE_VERSION = 1;
private static String DATABASE_CREATE =
"create table Payment (_id integer primary key autoincrement, "
+ "Date text not null,"+"CustomerName text not null,"+"Amount text not null,"+"Banks text not null);";
private static final String DATABASE_CREATECUS =
"create table Customer (_id integer primary key autoincrement, "
+ "BusinessName text not null,"+"Address text not null,"+"ContactPerson text not null,"+"PhoneNumber text not null,);";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public saveData(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db)
{
db.execSQL(DATABASE_CREATE);
db.execSQL(DATABASE_CREATECUS);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
int newVersion)
{
Log.w(TAG, "Upgrading database from version " + oldVersion
+ " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS titles");
onCreate(db);
}
}
public saveData open()throws SQLException
{
db=DBHelper.getWritableDatabase();
return this;
}
public void close()
{
DBHelper.close();
}
public long insert(String Date,String CustomerName,String Amount,String Banks) {
// TODO Auto-generated method stub
ContentValues cv=new ContentValues();
cv.put(KEY_DATE,Date);
cv.put(KEY_NAME,CustomerName);
cv.put(KEY_AMOUNT,Amount);
cv.put(KEY_BANK,Banks);
return db.insert(DATABASE_TABLE, null,cv);
}
public long insertForm(String BusinessName ,String Address ,String ContactPerson) {
// TODO Auto-generated method stub
ContentValues cv=new ContentValues();
cv.put(KEY_BUSNAME,BusinessName);
cv.put(KEY_ADD,Address);
cv.put(KEY_CPERSON,ContactPerson);
}
public Cursor getlatlng()
{
Cursor latlngCursor = db.rawQuery("select * from " + DATABASE_TABLE,null);
if (latlngCursor != null)
{
latlngCursor.moveToFirst();
}
db.close();
return latlngCursor;
}
public Cursor order()
{
Cursor latlngCursor = db.rawQuery("select * from " + DATABASE_TABLE2,null);
if (latlngCursor != null)
{
latlngCursor.moveToFirst();
}
db.close();
return latlngCursor;
}
}
Error Code =1 No Such table for Customer

use below two class
package Your 'packagename';
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DBHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "BistroDB";
private static final int DATABASE_VERSION =1;
// Database creation sql statement
public static final String Table1= "create table table1name ("Your cloumns");";
public static final String Table2 = "create table table2name ("Your cloumns");";
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Method is called during creation of the database
#Override
public void onCreate(SQLiteDatabase database) {
database.execSQL(table1);
database.execSQL(table2);
}
// Method is called during an upgrade of the database, e.g. if you increase
// the database version
#Override
public void onUpgrade(SQLiteDatabase database, int oldVersion,
int newVersion) {
Log.w(DBHelper.class.getName(),
"Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
database.execSQL("DROP TABLE IF EXISTS table1");
database.execSQL("DROP TABLE IF EXISTS table2");
onCreate(database);
}
public boolean deleteDatabase(Context context) {
return context.deleteDatabase(DATABASE_NAME);
}
}
Use below class to insert values into table
package 'Your package name';
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
public class DataBaseAdapter {
// Database fields
private Context context;
private SQLiteDatabase database;
private DBHelper dbHelper;
public DataBaseAdapter(Context context) {
this.context = context;
}
public DataBaseAdapter open() throws SQLException {
dbHelper = new DBHelper(context);
database = dbHelper.getWritableDatabase();
return this;
}
public void close() {
dbHelper.close();
}
public Cursor fetchAllTAble1data() {
return database.query("MenuData", new String[] { "id", "Title",
"Image", "Description" }, null, null, null, null, null);
}
public Cursor fetchAllTable2data() {
return database.query("RestaurantsData", new String[] {
"restaurant_id", "name", "phone", "email", "open_days",
"timing", "website", "loc_name", "street", "city", "longitude",
"latitude", "zip" }, null, null, null, null, null);
}
public void deleteTable(String tablename){
database.execSQL("drop table if exists "+tablename+';');
}
public void createIndividualTable(String query){
database.execSQL(query);
}
public void InsertTable1Data(TAble1 review) {
ContentValues values = new ContentValues();
values.put("Name", review.Name);
values.put("Email", review.Email);
values.put("Comment", review.Comment);
values.put("Rating", review.Rating);
database.insert("ReviewsData", null, values);
}
public void InsertTable2Data(TAble2 photos) {
ContentValues values = new ContentValues();
values.put("photo", photos.Photos);
database.insert("PhotosData", null, values);
}
public ContentValues createContentValues(String category, String summary,
String description) {
ContentValues values = new ContentValues();
return values;
}
}

Try removing the "," at the end of DATABASE_CREATECUS