Develop Reference

SQLite database's been created but not the table (android)

A lot of questions already have been asked about this but none of them seems to be working for me.
I open the file explorer>data>data>package name>database>mydatabase.db in order to get my database and i save it on my pc n try to see it using db browser for sqlite. But there's no table.
here's the helper class that extends sqliteOpenHelper:
package famiddle.smart.apps.businessmanager;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class BusinessDbHelper extends SQLiteOpenHelper {
// If you change the database schema, you must increment the database version.
public static final String DATABASE_NAME = "BusinessManager.db";
public static final int DATABASE_VERSION = 1;
// SQL query for creating the table for items name
private static final String SQL_CREATE_ITEMS_NAME_TABLE =
"CREATE TABLE itmes_name(id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, items_name TEXT NOT NULL);" ;
public BusinessDbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
sqLiteDatabase.execSQL(SQL_CREATE_ITEMS_NAME_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
}
In my one of app's activity, I instantiate above class and run a method getReadableDatabase() so that the database can be created with the table.
package famiddle.smart.apps.businessmanager;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import androidx.appcompat.app.AppCompatActivity;
public class PurchaseActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_purchase);
// Instantiate the subclass of SQLiteOpenHelper.
BusinessDbHelper dbHelper = new BusinessDbHelper(this);
SQLiteDatabase db = dbHelper.getReadableDatabase();
}
what do i do?

Everything is fine with this code. I wasn't extracting two other files with the database file and wasn't putting it into one folder. When I did put all three files into one folder and opened the file with .db extension using the db browser for SQLite, I could see the tables.

I cant call my constructor method SQLite

I'm new at the android studio. I tried creating SQLite Database but when I try inserting data android studio cannot resolve it. i also tried MainActivity.this and getApplicationContext instead of db=new DatabaseHelper(this); on this line. and on device monitor, it isn't creating a database file
MainActivity.java
package com.example.lenovo.sqlite_2_deneme;
import android.content.Context;
import android.media.midi.MidiDevice;
import android.provider.ContactsContract;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
DatabaseHelper db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db=new DatabaseHelper(this);
EditText et_name,et_surname,et_number;
Button btn_data;
et_name= (EditText) findViewById(R.id.et_isim);
et_surname= (EditText) findViewById(R.id.et_soyisim);
et_number= (EditText) findViewById(R.id.et_numara);
btn_data= (Button) findViewById(R.id.btn_veri);
btn_data.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
db.insertData();
}
});
}
}
and my DatabaseHelper class
package com.example.lenovo.sqlite_2_deneme;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.ContactsContract;
import android.widget.TableLayout;
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME= "student_info.db";
public static final String TABLE_NAME="student_table";
public static final String COL_1="ID";
public static final String COL_2="NAME";
public static final String COL_3="SURNAME";
public static final String COL_4="NUMBER";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE"+ TABLE_NAME+"(ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, SURNAME TEXT, NUMBER INTEGER)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS"+ TABLE_NAME);
this.onCreate(db);
}
public Boolean DataInsert(String name, String surname, String number)
{
SQLiteDatabase db=this.getWritableDatabase();
ContentValues contentValues=new ContentValues();
contentValues.put(COL_2,name);
contentValues.put(COL_3,surname);
contentValues.put(COL_4,number);
long sonuc= db.insert(TABLE_NAME,null,contentValues);
if(sonuc==-1)
return false;
else
return true;
}
}

Your database will be created at the instance when you call
SQLiteDatabase db=this.getWritableDatabase();
At the moment I dont see you have called this anywhere in your code. You have written a DataInsert method but it is not getting called in the code you have shared so far.

your'e sql query is wrong give the space in table (insert data),and also in onupgrade and there is no method insertData()
db.execSQL("CREATE TABLE "+ TABLE_NAME+"(ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, SURNAME TEXT, NUMBER INTEGER)");

There is no method insertData() . You should use
DataInsert() method .
db=new DatabaseHelper(MainActivity.this);
EditText et_name,et_surname,et_number;
Button btn_data;
et_name= (EditText) findViewById(R.id.et_isim);
et_surname= (EditText) findViewById(R.id.et_soyisim);
et_number= (EditText) findViewById(R.id.et_numara);
btn_data= (Button) findViewById(R.id.btn_veri);
btn_data.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
db.DataInsert(et_name.getText().toString(),et_surname.getText().toString(),et_number.getText().toString());
}
});
FYI
void onCreate (SQLiteDatabase db)
Called when the database is created for the first time.

xml string from class android

This code crashes the application, If i refer to database name from the static variable it works. When i try to get it from the strings.xml it crashes the app. Any idea why it fails? This is a class not an activity so i imported android.content.res.Resources. Also if i try context.getString it will also crash.
import android.content.Context;
import android.content.res.Resources;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
//public static final String DATABASE_NAME = "library.db";
public static final String TITLE = "title";
public static final String AUTHOR = "author";
public static final String ISBN = "isbn";
public DatabaseHelper(Context context) {
super(context, Resources.getSystem().getString(R.string.DATABASE_NAME), null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE books (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, author TEXT, isbn TEXT);");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}

You don't need to use a string resource for your database name, and in fact it doesn't make much sense to. String resources are mainly for anything the user will see so that you can provide alternative resources for other configurations (specifically, other languages). What you are providing is essentially a file name for your database. Since this is entirely internal to your app and the user will never see it, you should just use a static final String with the name you want for your database file.
/* Database file name */
private static final String BD_NAME = "something.db";
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, null);
}

it is wrong
super(context, Resources.getSystem().getString(R.string.DATABASE_NAME), null, 1);
Try This
super(context, context.getResources().getString(R.string.DATABASE_NAME), null, 1);

change
Resources.getSystem().getString(R.string.DATABASE_NAME)
to
context.getResources().getString(R.string.DATABASE_NAME)

Java code to call my method that adds information to SQLite database for Android app

I have 2 text fields on the screen and a button. When the button is pressed I want the information in the name text field to be passed to a variable, then run my addAccount() method in my DatabaseHelper.class, passing the variable into this method, this should store the variable information in an SQLite database.
Here is my Activity with the text field and button.
package mr.mwod.moneyorganiser;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class AddAccountActivity extends Activity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.addaccountlayout);
Button addAccountVairiable = (Button) findViewById(R.id.addAccountButton);
addAccountVairiable.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
EditText accountNameData = (EditText)findViewById(R.id.accountNameTextField);
String accountNameVairiable = accountNameData.getText().toString();
//Need the code here to run addAccount form DatabaseHelper.class
//accountName vairiable needs to be passed into the method as the information to store.
}
});
}
}
I have commented where I think the code needs to go and what it needs to do.
Here is my DatabaseHelper.class encase their are errors is in there.
package mr.mwod.moneyorganiser;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "money_organiser";
private static final String TABLE_ACCOUNTS = "accounts";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "account_name";
private static final String KEY_ACCOUNT_BALANCE = "account_balance";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_ACCOUNTS + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_ACCOUNT_BALANCE + " INTEGER" + ")";
db.execSQL(CREATE_CONTACTS_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_ACCOUNTS);
// Create tables again
onCreate(db);
}
public void addAccount(String name) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, name);
db.insert(TABLE_ACCOUNTS, null, values);
db.close();
}
}
Any help would be greatly appreciated.

Is there any trick in your question? Isn't just calling new DatabaseHelper(this).addAccount(accountNameVairiable); working? Of course it will make sense to reuse the variable, rather than allocating it every time, but I am almost sure this is not your problem.
By the way I would recommend you to change the name of the primary key column of the table. Use _id, some android helper methods will be easier to use in this way.
EDIT: I just noticed the call happens in anonymous class. This as noted by you will trigger a compilation error, because the listener is not a Context. The activity is. Luckily this can be very easily solved via placing what class exactly to use for the ocnstruction (using the parent Activity, which is a context).
new DatabaseHelper(AddAccountActivity.this).addAccount(accountNameVairiable);

It looks as if all you are missing is a call to DatabaseHelper.addAccount() at the lines you have highlighted.
Does this not work? If you are getting an error, then tell us what the problem is.
If you are wondering how to access the DatabaseHelper, then you could make it a singleton and refer to its instance when needed.

press the save button EditText value is stored in to the database

I have four EditText and two buttons namely, save and review button.
If i press the save button EditText value is stored in to the database and on clicking the review button saved value in the database is listed in ListView.
How is this done please anybody explain to me.
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.provider.BaseColumns;
public class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
super(context, "MedicinePill", null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS names3 ("
+ BaseColumns._ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, first VARCHAR, last VARCHAR ,dose2 VARCHAR ,dose3 VARCHAR)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Steps to upgrade the database for the new version ...
}
}
//this is my database class in this where i add the insert data from the database
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class Medical extends Activity
{
Button AddMedicine,ReviewMedicine;
EditText dose1,dose2,dose3;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
AddMedicine = (Button)findViewById(R.id.add);
ReviewMedicine = (Button)findViewById(R.id.rev);
dose1 = (EditText)findViewById(R.id.Edit1);
AddMedicine.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
String s1 = dose1.getText().toString();
// TODO Auto-generated method stub
}
});
}
}
//and this is my activity class
how i add edittext value in to database pls any body help me!!!!!!!!

You need to create class insertdose in DatabaseHelper like this:
public long insertdose(String dose1)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_dose, dose1);
return db.insert(DATABASE_TABLE, null, initialValues);
}
and call it at your onClick view

You will need to create a method in the DatabaseHelper class that takes in four strings and adds them to your database.
Then in your onClick() method in your Medical activity class you can get the string values from your 4 EditText fields and call your method with these values.
I would recommend going through the Notepad Tutorial. This should provide a good example of what you want to do.