Develop Reference

Why am I not able to fetch the code from the DataBase?

I'm unable to fetch the data although I'm able to add data. I have two questions here: What is the purpose of the primary key and how can I implement it? In my code, if I give the same values multiple times then it also gets accepted.
//Check this statement
db.execSQL("create table mtable (_Id Integer auto_increment, name Text Primary key , mail Text)");
Now,my 2nd major problem..
Why am I not able to fetch the data from the database ?
My two java classes are as follows:
MainActivity.java
package com.apna.mydatabase;
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
Button save,fetch,update,Delete;
EditText edtname,edtmail,afetch;
MySqlOpenHelper ab,db;
SQLiteDatabase sql,sql1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edtname=(EditText) findViewById(R.id.editText1);
edtmail=(EditText)findViewById(R.id.editText2);
afetch=(EditText) findViewById(R.id.editText3);
save=(Button) findViewById(R.id.button1);
fetch=(Button) findViewById(R.id.button2);
update=(Button) findViewById(R.id.button3);
Delete=(Button)findViewById(R.id.button4);
save.setOnClickListener(this);
fetch.setOnClickListener(this);
ab=new MySqlOpenHelper(MainActivity.this);
sql=ab.getWritableDatabase();
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch(v.getId())
{
case R.id.button1:
ContentValues cv=new ContentValues();
cv.put("name", edtname.getText().toString());
cv.put("mail",edtmail.getText().toString());
long result=sql.insert("mtable", "nullCo", cv);
if (result>0)
{
Toast.makeText(MainActivity.this, "Saved at"+result, 5000).show();
edtname.setText(" ");
edtmail.setText(" ");
}
else
{
Toast.makeText(MainActivity.this, "Not Saved"+result, 5000).show();
}
break;
case R.id.button2:
db= new MySqlOpenHelper(MainActivity.this);
sql1=db.getReadableDatabase();
String a=afetch.getText().toString();
Cursor c=sql1.rawQuery("Select * from mtable where _id ="+a,null );
String str=null,str1=null;
if(c.getCount()>0)
{
while(c.moveToNext())
{
str=c.getString(c.getColumnIndex("name"));
str1=c.getString(c.getColumnIndex("mail"));
}
edtname.setText(str);
edtmail.setText(str1);
}
else
{
Toast.makeText(MainActivity.this,"Invalid record",5000 ).show();
}
}
}
}
MySqlOpenHelper.java
package com.apna.mydatabase;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class MySqlOpenHelper extends SQLiteOpenHelper {
public MySqlOpenHelper(Context context)
{
super(context, "Mynew", null,1);
}
#Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL("create table mtable (_Id Integer auto_increment, name Text Primary key , mail Text)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
It would be my pleasure to get the required results.

what the purpose of primary key
A primary key is a special relational database table column (or combination of columns) designated to uniquely identify all table records.
A primary key’s main features are:
It must contain a unique value for each row of data.
It cannot contain null values.
See reference.
how to implement it
Primary Key can also be a composite key meaning two columns say in your case _Id and name could both be primary key. Satisfying the above conditions.
EDIT:
It is not advisable to have only name as the primary key since names can recur and defeat the purpose of the primary key. For a composite key you could :
db.execSQL("create table mtable (_Id Integer auto_increment, name Text not null,primary key (_Id,name) , mail Text)")
Simply put I have achieved it as:
create table mtable (_Id Integer identity, name varchar not null,primary key (_Id,name) , mail Text)
For example:
If you enter name say Anand and insert the record. Say another person is name Anand you insert it again it would defeat the purpose of the primary key as in relational databases it is meant to uniquely identify a record which in this case won't happen.
if i give same values multiple times then it also accept it
You can insert multiple values having the same primary key because you haven't specified your primary key to be unique or identity as in :
db.execSQL("create table mtable (_Id Integer auto_increment, name Text Primary key , mail Text)");
Why am I not able to fetch the data from the database ?
Your code seems to be fine. Debug it and see if the cursor contains anything and is not null. You could check first:
if (cursor != null) {
//move cursor to first row
if (cursor.moveToFirst()) {
do {
// Get version from Cursor
String name = cursor.getString(cursor.getColumnIndex("name"));
//more code
// move to next row
} while (cursor.moveToNext());
}
}
Update:
If you try to reinsert a row with the same primary key you would get the error that primary key should be unique and the primary key includes in itself the not null and unique traits so no need to specify these with it.

What should I use for SQLite database

Ok, so here is my dilemma. I j ust started working with SQLite database's in android and I came across the Notepad Tutorial on the Android Developer website. Now I thought that this was pretty cool and was messing around with it until I noticed that Android Studio said that some of the code was deprecated.
One of the deprecated code was startManagingCursor. I decided to look into it more and found something called a CursorLoader with a ContentProvider, so I decided to look them up and it seems like the CursorLoader with a ContentProvider is a better choice. The problem is that I can't find a decent example that doesn't go into outrageous complexity. Like I said I just started learning this and I would like not to sit and try to figure out what someone else's code does for 3 hours.
So are there any good tutorials or examples that don't over complicate this topic so that I have a chance to learn it?

Example Code
package com.prgguru.example;
 
import java.util.ArrayList;
 
import android.app.ListActivity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Toast;
 
public class SQLiteCrudExample  extends ListActivity {
    //DB name
    private final String dbName = "Android";
    //Table name
    private final String tableName = "Versions";
    //String array has list Android versions which will be populated in the list
    private final String[] versionNames= new String[]{"Cupcake", "Donut", "Eclair", "Froyo", "Gingerbread", "Honeycomb", "Ice Cream Sandwich", "Jelly Bean", "Kitkat"};
    #Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ArrayList<String> results = new ArrayList<String>();
        //Declare SQLiteDatabase object
        SQLiteDatabase sampleDB = null;
         
        try {
            //Instantiate sampleDB object
            sampleDB =  this.openOrCreateDatabase(dbName, MODE_PRIVATE, null);
            //Create table using execSQL
            sampleDB.execSQL("CREATE TABLE IF NOT EXISTS " + tableName +    " (versionname VARCHAR);");
            //Insert Android versions into table created
            for(String ver: versionNames){
                sampleDB.execSQL("INSERT INTO " + tableName + " Values ('"+ver+"');");
            }
             
            //Create Cursor object to read versions from the table
            Cursor c = sampleDB.rawQuery("SELECT versionname FROM " + tableName, null);
            //If Cursor is valid
            if (c != null ) {
                //Move cursor to first row
                if  (c.moveToFirst()) {
                    do {
                        //Get version from Cursor
                        String firstName = c.getString(c.getColumnIndex("versionname"));
                        //Add the version to Arraylist 'results'
                        results.add(firstName);
                    }while (c.moveToNext()); //Move to next row
                }
            }
             
            //Set the ararylist to Android UI List
            this.setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,results));
             
        } catch (SQLiteException se ) {
            Toast.makeText(getApplicationContext(), "Couldn't create or open the database", Toast.LENGTH_LONG).show();
        } finally {
            if (sampleDB != null) {
                sampleDB.execSQL("DELETE FROM " + tableName);
                sampleDB.close();
            }
        }
    }
}
===
There is an example source code here to download
Also try this links:
http://www.androidhive.info/2013/09/android-sqlite-database-with-multiple-tables/
http://developer.android.com/training/basics/data-storage/databases.html
http://www.vogella.com/tutorials/AndroidSQLite/article.html
http://www.tutorialspoint.com/android/android_sqlite_database.htm

SQLite database in Android, causes application crash

I'm testing SQLite database in android for the first time.
My program stops as I open it, and i cannot check it, i was wondering if there is a mistake in my code, or database connection,
any help will be appreciated :)
this is my Main.java file:
package de.blattsoft.SQLite;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.Menu;
public class Main extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SQLiteDatabase db = openOrCreateDatabase("MyDB", MODE_PRIVATE, null);
Cursor c = db.rawQuery("SELECT * FROM MyTable", null);
c.moveToFirst();
Log.d("Ali", c.getString(c.getColumnIndex("FirstName")));
db.close();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Note: I have asked this question many times ago, and I have written the full answer of how to implement databases in Android in the answers bellow.

First of all you need to create a database, then insert some data in it an then try to display.
What you are doing is ,if database is not there then create and select the column and display. It will obviously fail and your app crash.
Do something like
public void onCreate(SQLiteDatabase db) {
/*CREATE LOGIN TABLE*/
String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + "("
+ KEY_ID + " INTEGER PRIMARY KEY,"
+ KEY_NAME + " TEXT," + ")";
db.execSQL(CREATE_LOGIN_TABLE);
}
Then do this ,
public void addMessage(String id, String name){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, id); //
values.put(KEY_NAME, name);
db.insert(TABLE_NAME, null, values);
db.close(); // Closing database connection
}
Then you can display ,

You haven't created the database. And inserting or fetching values from the structure which doesn't exist will lead to crash your app. It's like climbing a building which doesn't exist.
So, first create the database then do rest of the things.
For better understanding follow the you tube video tutorial of Slidenerd. They have sequentially explained all the things for beginners here.
Hope it will help.

I have asked this question many times ago when I was an Android noob! :D
right now this is the way I recommend you to use android sqlite database using helper classes.
as an overview, we need to create two classes, DatabaseHelper class
and DataSource class.
What we need to create:
The DatabaseHelper class must extend SQLiteOpenHelper which is a built-in Android class from android.database.sqlite package and its purpose is to manage database creation and version management.
The DataSource class uses our helper class to implement methods which you need for your application.
For Example, we're going to create a database which has one table called users, and the table has 2 columns: id and name;
The id is going to be used as the primary key.
So, let's create the helper class:
DatabaseHelper.java:
package com.mpandg.android.dbtest;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DatabaseHelper extends SQLiteOpenHelper {
// this tag is used for logging purposes.
public static final String TAG = "database";
// database version.
public static final int DATABASE_VERSION = 1;
// database file name.
public static final String DATABASE_NAME = "database.db";
// table details:
public static final String TABLE_USERS = "users";
public static final String USERS_COLUMN_ID = "id";
public static final String USERS_COLUMN_NAME = "name";
// query of creating users table.
public static final String CREATE_USERS_TABLE =
"CREATE TABLE " + TABLE_USERS + " (" +
USERS_COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
USERS_COLUMN_NAME + " TEXT" + ")";
// query string of deleting users table.
public static final String DELETE_TABLES =
"DROP TABLE IF EXISTS " + TABLE_USERS + ";";
// constructor method which takes the context and passes it
// to appropriate super method with other database details
// which creates the database.
public DatabaseHelper(Context context) {
// creates the database using given information.
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
// this line executes the query we made earlier
// to create the users table.
db.execSQL(CREATE_USERS_TABLE);
// log the table creation for debugging.
Log.i(TAG, TABLE_USERS + " has been created.");
}
// whenever you give a new update for your application,
// if you change the version of the database, this method
// will be called, you can do your own complicated operations
// on your tables if you need, but right now, I just delete
// the old table and I make an explicit call to onCreate
// method to create the tables again.
// but never forget that you should never make explicit
// calls to onCreate method, but this is an exception here.
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// execute the delete query we made earlier.
db.execSQL(DELETE_TABLES);
// explicit call to onCreate. (read the comment above method)
onCreate(db);
}
}
As you see, we have actually created a subclass of SQLiteOpenHelper and we have implemented onCreate(SQLiteDatabase) and onUpgrade(SQLiteDatabase, int, int) methods, and the helper class we created, takes care of opening the database if it exists, creating it if it does not exist and upgrading it if it's necessary.
Now it's time to use the helper class we created and write our methods to use the database in DataSource class.
We will create a database object and we will instantiate it using the methods in our helper class, and we create methods to insert, select and delete.
So, Let's create DataSource.java:
package com.mpandg.android.dbtest;
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;
import java.util.ArrayList;
import java.util.List;
public class DataSource {
// create an instance of SQLiteOpenHelper
// but we're going to instantiate it using
// the helper class we created earlier.
SQLiteOpenHelper dbHelper;
// the main database object which will be
// instantiated using the helper class methods.
SQLiteDatabase dataBase;
private final String TAG = "dataSource";
// an string array holding our table's column names
// which is going to be used by database methods.
public static final String[] usersTableColumns = {
DatabaseHelper.USERS_COLUMN_ID,
DatabaseHelper.USERS_COLUMN_NAME
};
// constructor which receives the activity context.
public DataSource(Context context){
// instantiate the dbHelper object using our DatabaseHelper class.
dbHelper = new DatabaseHelper(context);
}
public void open(){
// opening the database or
// creating the table structures for the first time.
// the helper class knows when to open or create the database.
dataBase = dbHelper.getWritableDatabase();
// log the event for debugging purposes.
Log.i(TAG, "database opened");
}
public boolean isOpen () {
// check if the database is already open.
return dataBase.isOpen();
}
public void close(){
// close the database.
dataBase.close();
// log the event for debugging purposes.
Log.i(TAG, "database closed");
}
// insert a name record into database .
public void insertName (String name) {
// ContentValues implements a map interface.
ContentValues values = new ContentValues();
// put the data you want to insert into database.
values.put(DatabaseHelper.USERS_COLUMN_NAME, name);
// passing the string array which we created earlier
// and the contentValues which includes the values
// into the insert method, inserts the values corresponding
// to column names and returns the id of the inserted row.
long insertId = dataBase.insert(DatabaseHelper.TABLE_USERS , null, values);
// log the insert id for debugging purposes.
Log.i(TAG, "added name id:" + insertId);
}
// returns a list of string
// containing the names saved in the database.
public List<String> getNames (){
List<String> names;
// creating the cursor to retrieve data.
// cursor will contain the data when the
// query is executed.
Cursor cursor = dataBase.query(DatabaseHelper.TABLE_USERS, usersTableColumns,
null, null, null, null, null);
// log the number of returned rows for debug.
Log.i(TAG, "returned: " + cursor.getCount() + " name rows .");
// check if the cursor is not null.
if(cursor.getCount()>0){
// instantiate the list.
names = new ArrayList<>();
// cursor starts from -1 index, so we should call
// moveToNext method to iterate over the data it contains.
while (cursor.moveToNext()) {
// read the string in the cursor row using the index which is the column name.
String name = cursor.getString(cursor.getColumnIndex(DatabaseHelper.USERS_COLUMN_NAME));
// log the retrieved name.
Log.i(TAG, "name retrieved:" + name);
// now add the retrieved name into the list.
names.add(name);
}
// now we have the names in our string list
return names;
} else {
// if the cursor was empty, it means that
// there was no name found in the table,
// so return null.
return null;
}
}
// returns a name corresponding to given id.
public String findNameById (long id){
String name;
// the where clause which is our condition.
String whereClause = DatabaseHelper.USERS_COLUMN_ID + " = ?";
// the arguments passed to
// the where clause. (here is only one argument)
String[] whereArgs = {id+""};
// creating the cursor to retrieve data.
// cursor will contain the data when the
// query is executed.
Cursor cursor = dataBase.query(DatabaseHelper.TABLE_USERS, usersTableColumns,
whereClause, whereArgs, null, null, null);
// log the number of returned rows for debug.
// (logically it should return one row here)
Log.i(TAG, "returned: " + cursor.getCount() + " name rows .");
// check if the cursor is not null.
if(cursor.getCount()>0){
// cursor starts from -1 index, so we should call
// moveToNext method to iterate over the data it contains.
cursor.moveToNext();
// read the string in the cursor row using the index which is the column name.
name = cursor.getString(cursor.getColumnIndex(DatabaseHelper.USERS_COLUMN_NAME));
// log the retrieved name.
Log.i(TAG, "name retrieved:" + name);
return name;
} else {
// if the cursor was empty, it means that
// there was no name found with given id,
// so return null.
return null;
}
}
// delete a name from the table.
public void deleteName (String name) {
// where statement of our delete method.
String whereClause = DatabaseHelper.USERS_COLUMN_NAME + "=" + "?";
// the arguments passed to
// the where clause. (here is only one argument)
String[] whereArgs = {name};
// execute the delete query with delete method.
int deleteId = dataBase.delete(DatabaseHelper.TABLE_USERS , whereClause, whereArgs);
// log the id of the deleted row.
Log.i(TAG, "deleted name id:" + deleteId);
}
}
Now that we have done writing the necessary classes to create and use our database in an appropriate way, it's time to use the methods we wrote in our DataSource class.
All you have to do, is to create an object of DataSource class in your activity and use the methods in it.
when you are intending to use the database, you should open it, you can simply do it by the open() method we wrote in our DataSource class, and after you are done, you must close it to avoid leaks; you can close it using the close() method in 'DataSource` class.
For example, you have some users and you want to add them in the database:
// create the dataSource object
// "this" refers to the activity.
DataSource dataSource = new DataSource(this);
// open the dataBase
dataSource.open();
// insert the names.
dataSource.insertName("Amy");
dataSource.insertName("Johnny");
dataSource.insertName("Abbey");
dataSource.insertName("Miley");
// close the database.
dataSource.close();
Or you want to log all the users in the database:
//TAG for debug logs.
String TAG = "db log";
// create the dataSource object
// "this" refers to the activity.
DataSource dataSource = new DataSource(this);
// open the dataBase
dataSource.open();
// get the names.
List<String> names = dataSource.getNames();
// log all the names in the list.
for (String name: names) {
Log.i(TAG, "retrieved name:" + name);
}
// close the database.
dataSource.close();
Or you want to find a name by its id:
//TAG for debug logs.
String TAG = "db log";
// create the dataSource object
// "this" refers to the activity.
DataSource dataSource = new DataSource(this);
// open the dataBase
dataSource.open();
// find the name by id.
String name = dataSource.findNameById(1);
// log the retrieved name wit id:1.
Log.i(TAG, "retrieved name:" + name);
// close the database.
dataSource.close();
Finally if you want to delete a name:
// create the dataSource object
// "this" refers to the activity.
DataSource dataSource = new DataSource(this);
// open the dataBase
dataSource.open();
// delete the given name
dataSource.deleteName("Amy");
// close the database.
dataSource.close();
That's it.
This is a basic structure for creating databases in Android, as you can see, you can add other tables and columns, easily by adding your own code to the helper class and your own methods to use them in the DataSource class.

Try this
package ir.itstuff.SQLite;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.Menu;
public class Main extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
(EditText) fName = (EditText)findViewById(R.id.editText1);
(EditText) sName = (EditText)findViewById(R.id.editText2);
(Button) save = (Button)findViewById(R.id.button1);
SQLiteDatabase db = openOrCreateDatabase("MyDB", MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS MyTable(id INTEGER PRIMARY KEY AUTOINCREMENT, FirstName varchar,SecondName varchar);")
//Inserting data from inputs
save.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String first_name = fName.getText().toString();
String second_name = sName.getText().toString();
String insert_data="INSERT INTO MyTable (FirstName,SecondName) VALUES " + "('" + first_name + "'," + "'" + second_name + "'" + ")";
shoppingListDB.execSQL(insert_data);
Toast.makeText(getBaseContext(), "Data Inserted", Toast.LENGTH_LONG).show();
Cursor cr=shoppingListDB.rawQuery("SELECT * FROM MyTable;", null);
if (cr.moveToFirst()){
do{
String name = cr.getString(cr.getColumnIndex("FirstName"));
}
while (cr.moveToNext());
Toast.makeText(getBaseContext(), name, Toast.LENGTH_LONG).show;
}
cr.close();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}

Sqlite column id is not unique

below is my code i just want to display the data i inserted in the sqlite database to a text view but i have this error saying that the id is not unique.
package com.example.sqlitetest;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;
public class Main extends Activity {
TextView scrName, fName;
Button go;
SQLiteDatabase db;
String screenName, fullName;
Cursor cursor;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
db = openOrCreateDatabase("MyDataBase", MODE_PRIVATE, null);
db.execSQL("CREATE TABLE if not exists MyTable(ScreenName Varchar, FullName Varchar, id int(3) PRIMARY KEY);");
db.execSQL("Insert into MyTable VALUES('joff', 'tiquez', 1);");
cursor = db.rawQuery("Select * from MyTable", null);
cursor.moveToFirst();
scrName = (TextView) findViewById(R.id.scrName);
fName = (TextView) findViewById(R.id.fName);
while(cursor.isAfterLast() == false){
//retrieving the data from sqlite (im not sure if im doing it right)
String screenname = cursor.getString(cursor.getColumnIndex("ScreenName"));
String fullname = cursor.getString(cursor.getColumnIndex("FullName"));
//this are the textview
scrName.setText(screenname);
fName.setText(fullname);
cursor.moveToNext();
}
db.close();
}
}
this is my whole java code. thanks :)

Well I think this project works fine when you run it first time. When you run it second time it gives error because id is your primary key and the row with the id 1 has been already inserted to your database.
To get rid of errors either :
1) uninstall the app and run it again
2) Don't make id as primary key
3) Catch the exception and handle it yourself

Might I suggest an alternative to this. What you can do is make the id column autoincrement as well while still keeping that column as primary key
EDIT:-
Also I have some other suggestions for you:-
db.execSQL("Insert into MyTable VALUES('joff', 'tiquez', 1);");
you can user ContentValues instead
while(cursor.isAfterLast() == false){
could be replaced with while(!cursor.isAfterLast()){. Looks cleaner this way.
Or you could directly replace while(cursor.isAfterLast() == false){ with while(cursor.moveToNext()){ and can remove out cursor.moveToNext(); from the while block.
Happy Coding!!!

Table not found issue in SQLite

I have written a code that get information from json file related to specific YouTube video and then stores the information I need in my database.
The parsing from json file has no problem. when I am trying to insert values in my database an error message appears telling me that no such table exists.
Here is the stack-trace:
07-31 08:42:22.451: I/Database(365): sqlite returned: error code = 1,
msg = no such table: youtube_VIDEOS 07-31 08:42:22.471: E/Database(365):
Error inserting video_CommentCount=70 video_CountView=50 video_Name=Badly
Drawn Boy - Disillusion (directed by Garth Jennings)
video_Url=https://www.youtube.com/watch?v=B11msns6wPU&feature=youtube_gdata_player
video_LIKES=60 video_Img=https://i1.ytimg.com/vi/B11msns6wPU/default.jpg
video_Descrption=My new playlist Description 07-31 08:42:22.471:
E/Database(365): android.database.sqlite.SQLiteException:
no such table: youtube_VIDEOS: ,
while compiling: INSERT INTO youtube_VIDEOS(video_CommentCount, video_CountView, video_Name, video_Url,video_LIKES, video_Img, video_Descrption) VALUES(?, ?, ?, ?, ?, ?, ?);
07-31 08:42:22.471: E/Database(365): at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
And here is my database code:
package com.example.tstnetconnwithjson.db;
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 youtube_db extends SQLiteOpenHelper {
public static final String dataBase_NAME="YOUTUBE_database";
private static final int dataBase_VERSION=1;
private static final String dataBase_TABLE="youtube_VIDEOS";
public static final String[] COLS_List={"video_Name","video_Descrption","video_Img","video_Url","video_CountView","video_LIKES","video_CommentCount"};
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//end of declaring attributes and tables conents
public youtube_db(Context context) {
super(context,dataBase_NAME, null, dataBase_VERSION);
// TODO Auto-generated constructor stub
}
#Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(
"create table" + dataBase_NAME + "(" + COLS_List[0] +" text not null , "+ COLS_List[1]
+" text not null , "+ COLS_List[2]+" text not null , "+COLS_List[3]+" text not null , "+COLS_List[4]+" integer , "+COLS_List[5]
+" integer , "+COLS_List[6]+" integer ) ");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
Log.i("in the upgrade", "ok");
}
}
And here is the function that would insert the information in my database:
package com.example.tstnetconnwithjson.db;
import com.example.tstnetconnwithjson.tables.videos;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
public class youtubeDataBaseManager {
SQLiteDatabase SQL_db;
youtube_db my_Database;
public youtubeDataBaseManager(Context c){
my_Database=new youtube_db(c);
SQL_db= my_Database.getWritableDatabase();
}//end of costructor
public long insert_Youtube_Info( videos video){
ContentValues contentValues = new ContentValues();
contentValues.put(youtube_db.COLS_List[0], video.getVideoname());
contentValues.put(youtube_db.COLS_List[1], video.getDecscrption());
contentValues.put(youtube_db.COLS_List[2], video.getImageurl());
contentValues.put(youtube_db.COLS_List[3], video.getVediourl());
contentValues.put(youtube_db.COLS_List[4], "50");
contentValues.put(youtube_db.COLS_List[5], "60");
contentValues.put(youtube_db.COLS_List[6], "70");
long addResult ;
addResult= SQL_db.insert(youtube_db.dataBase_TABLE, null, contentValues);
if(addResult==-1)
{
Log.i("add video", "add error.... ");
}
else
{
Log.i("add video", "add:ok.... ");
}
return addResult;
}
Can anyone tell me what is the problem?

"create table" + dataBase_NAME + "("
You are missing space between name and <create table> keyword. You have to change it to:
"create table " + dataBase_TABLE + "("
Otherwise, your DDL statement won't work.
Later, you try and reference a table called "youtube_VIDEOS", which doesn't exist. Because you never created it. It's all about typo.

you should change here:
create table" + dataBase_TABLE+ "(" + COLS_List[0] +" text not null , "+ COLS_List[1]
+" text not null , "+ COLS_List[2]+" text not null , "+COLS_List[3]+" text not null , "+COLS_List[4]+" integer , "+COLS_List[5]
+" integer , "+COLS_List[6]+" integer ) ");

You have that error, because your table in database didn't successfully created. Why ? Because your table hasn't got primary key (id). Add, e.g :
`_id` INT PRIMARY KEY AUTOINCREMENT,
And now every thing should work correctly