Getting error while executing getwritabledatabase() in android

Question

I have created one class for database and multiple classes for tables and multiple activity classess everything works fine when I use the database class instance in activity class but at the same time when I use the database class instance in table class and run the application as soon as the control goes to getwritabledatabase I am getting exception and application is exited, below is the code for all 3 classes.

Database class.

public class Database extends SQLiteOpenHelper{

    private static  String dbname="Manager";
    private static int dbversion=2;
    SQLiteDatabase db;

    public Database(Context context) {

        super(context, dbname, null, dbversion);
        // TODO Auto-generated constructor stub
        db=this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        StockTable st=new StockTable();
        db.execSQL(st.stocktable);
        }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }

}

Activity class

public class stockmanager extends Activity{

    String getentry=null;
    Database d=new Database(this);
    StockTable st=new StockTable();


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.stockmanager);

    final Button AddStock=(Button) findViewById(R.id.button1);
        final EditText entry=(EditText) findViewById(R.id.editText1);
        final Button BroDetail=(Button) findViewById(R.id.button2);

        AddStock.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                getentry=entry.getText().toString();
                d.db.insert(st.tablename, null,st.insert());


            }
        });
                }
}

Table Class

    public class StockTable {

    Context c1;
    Database d1=new Database(c1);
    final String tablename="StockTable";
    private String column1="Stock_ID";
    private String column2="StockName";


    final String stocktable = "CREATE TABLE " + tablename + 
                " (" + column1+ " INTEGER PRIMARY KEY , " + column2 + " TEXT) ";

    public ContentValues insert(){

String select="Select StockID from Stocktable";

d.db.execsql(select);
        ContentValues cvi=new ContentValues();
        for(int i=0;i<=sm.getentry.length();i++)
        {
            cvi.put(column1, 1);
            cvi.put(column2,sm.getentry);
                        }

        return cvi;
    }

    public void delete(){


    }

First when control goes to getwritabledatabase of database class from activity class then it is executing but after when control from stock table class goes to database class and executes getwritabledatabase exception is occurred, Unfortunately I am unable to paste the exceptions here.

Can anyone please help me to solve this ?

Logcat

02-07 10:06:09.624: D/libEGL(10756): loaded /system/lib/egl/libEGL_genymotion.so
02-07 10:06:09.628: D/(10756): HostConnection::get() New Host Connection established 0xb87f5e00, tid 10756
02-07 10:06:09.720: D/libEGL(10756): loaded /system/lib/egl/libGLESv1_CM_genymotion.so
02-07 10:06:09.748: D/libEGL(10756): loaded /system/lib/egl/libGLESv2_genymotion.so
02-07 10:06:10.024: W/EGL_genymotion(10756): eglSurfaceAttrib not implemented
02-07 10:06:10.044: E/OpenGLRenderer(10756): Getting MAX_TEXTURE_SIZE from GradienCache
02-07 10:06:10.196: E/OpenGLRenderer(10756): Getting MAX_TEXTURE_SIZE from Caches::initConstraints()
02-07 10:06:10.212: D/OpenGLRenderer(10756): Enabling debug mode 0
02-07 10:07:17.328: W/EGL_genymotion(10756): eglSurfaceAttrib not implemented
02-07 10:07:19.820: I/Choreographer(10756): Skipped 36 frames!  The application may be doing too much work on its main thread.
02-07 10:07:22.556: W/EGL_genymotion(10756): eglSurfaceAttrib not implemented
02-07 10:07:22.788: I/Choreographer(10756): Skipped 44 frames!  The application may be doing too much work on its main thread.
02-07 10:07:28.064: D/dalvikvm(10756): GC_FOR_ALLOC freed 105K, 1% free 16944K/17072K, paused 37ms, total 40ms
02-07 10:07:30.524: I/System.out(10756): asdfdw
02-07 10:07:30.576: D/AndroidRuntime(10756): Shutting down VM
02-07 10:07:30.612: W/dalvikvm(10756): threadid=1: thread exiting with uncaught exception (group=0xa4b6e648)
02-07 10:07:30.652: E/AndroidRuntime(10756): FATAL EXCEPTION: main
02-07 10:07:30.652: E/AndroidRuntime(10756): android.database.sqlite.SQLiteException: unknown error (code 0): Queries can be performed using SQLiteDatabase query or rawQuery methods only.
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteConnection.nativeExecuteForChangedRowCount(Native Method)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteConnection.executeForChangedRowCount(SQLiteConnection.java:734)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteSession.executeForChangedRowCount(SQLiteSession.java:754)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1674)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1603)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at com.example.portfoliomanager.StockTable.insert(StockTable.java:43)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at com.example.portfoliomanager.stockmanager$1.onClick(stockmanager.java:36)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.view.View.performClick(View.java:4240)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.view.View$PerformClick.run(View.java:17721)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.os.Handler.handleCallback(Handler.java:730)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.os.Looper.loop(Looper.java:137)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at android.app.ActivityThread.main(ActivityThread.java:5103)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at java.lang.reflect.Method.invokeNative(Native Method)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at java.lang.reflect.Method.invoke(Method.java:525)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
02-07 10:07:30.652: E/AndroidRuntime(10756):    at dalvik.system.NativeStart.main(Native Method)
02-07 10:07:34.288: I/Process(10756): Sending signal. PID: 10756 SIG: 9
02-07 10:07:36.624: D/libEGL(10871): loaded /system/lib/egl/libEGL_genymotion.so
02-07 10:07:36.644: D/(10871): HostConnection::get() New Host Connection established 0xb87f5e70, tid 10871
02-07 10:07:36.784: D/libEGL(10871): loaded /system/lib/egl/libGLESv1_CM_genymotion.so
02-07 10:07:36.784: D/libEGL(10871): loaded /system/lib/egl/libGLESv2_genymotion.so
02-07 10:07:37.104: W/EGL_genymotion(10871): eglSurfaceAttrib not implemented
02-07 10:07:37.108: E/OpenGLRenderer(10871): Getting MAX_TEXTURE_SIZE from GradienCache
02-07 10:07:37.132: E/OpenGLRenderer(10871): Getting MAX_TEXTURE_SIZE from Caches::initConstraints()
02-07 10:07:37.132: D/OpenGLRenderer(10871): Enabling debug mode 0

@BirajZalavadia At this moment I don't have logs so can't post them — Siva, Feb 06 '14 at 06:13

M D · Answer 1 · 2014-02-06T06:18:32.743

1

You should replace this

String select="Select StockID from Stocktable";

With

String select="Select Stock_ID from Stocktable";

And also initialized your Context C1. Create Constructor that passed current Context into StockTable like:

public StockTable(Context cxnt){
this.c1=cxnt;
d1=new Database(c1);
 }

And add this

 StockTable st=new StockTable(this);

into your stockmanager activity.

edited Feb 06 '14 at 06:18

answered Feb 06 '14 at 06:12

M D

47,665
9
93
114

@M D I have tried this but still when control goes to `getwritabledatabase` I am getting exception – Siva Feb 06 '14 at 06:16
Thanks will surely give a try. – Siva Feb 06 '14 at 06:21

Biraj Zalavadia · Accepted Answer · 2014-02-07T10:26:48.023

Error is because you trying to access database with null context. So you need to initialize c1 before passing to Database constructor.

I just Edit your StockTable.java try this

import android.content.ContentValues;
import android.content.Context;

public class StockTable {

    Context c1;
    Database d1;
    final String tablename = "StockTable";
    private String column1 = "Stock_ID";
    private String column2 = "StockName";

    final String stocktable = "CREATE TABLE " + tablename + " (" + column1 + " INTEGER PRIMARY KEY , " + column2 + " TEXT) ";


    public StockTable(Context mContext){
        c1= mContext;
        d1= new Database(c1);
    }
    public ContentValues insert() {


        ContentValues cvi = new ContentValues();
        for (int i = 0; i <= sm.getentry.length(); i++) {
            cvi.put(column1, 1);
            cvi.put(column2, sm.getentry);
        }

        return cvi;
    }

    public void delete() {

    }
}

How to Use?

public class stockmanager extends Activity {

    String getentry = null;
    Database d;
    StockTable st;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.stockmanager);

        d = new Database(this.getApplicationContext());
        st = new StockTable(this.getApplicationContext());

        final Button AddStock = (Button) findViewById(R.id.button1);
        final EditText entry = (EditText) findViewById(R.id.editText1);
        final Button BroDetail = (Button) findViewById(R.id.button2);

        AddStock.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                getentry = entry.getText().toString();
                d.db.insert(st.tablename, null, st.insert());

            }
        });
    }
}

UPDATE YOUR Database Class

public class Database extends SQLiteOpenHelper {

    private static String dbname = "Manager";
    private static int dbversion = 2;
    SQLiteDatabase db;
    private Context mContext;

    public Database(Context context) {

        super(context, dbname, null, dbversion);
        // TODO Auto-generated constructor stub
        mContext = context;
        db = this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        StockTable st = new StockTable(mContext);
        db.execSQL(st.stocktable);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub

    }

}

Thanks for your reply I can't try now but will use the code and will post reply. — Siva, Feb 06 '14 at 06:21
I have tried your suggestion but now in database class where I have created object for stock table is prompting to enter context but what should I enter there as there is no context in database class. please help — Siva, Feb 07 '14 at 09:42
Thanks @Biraj problem is with database class first class in my question there I created object for Stock table there it is epecting context what to do in that case. — Siva, Feb 07 '14 at 09:51
I got the above error update by question with logcat.. can you please suggest what is the problem. — Siva, Feb 07 '14 at 10:08

user3264399 · Answer 3 · 2014-02-06T06:17:52.240

0

StockID & Stock_ID are two different column name.

While creating table you are using Stock_ID as column and while firing select query you are using StockID as column, that's your mistake. Your query should be

String select="Select Stock_ID from Stocktable";

And also initialized your Context C1. Create Constructor that passed current Context into StockTable like:

public StockTable(Context cxnt){
this.c1=cxnt;
 }

edited Feb 06 '14 at 06:17

answered Feb 06 '14 at 06:09

user3264399

284
1
13

have tried this but still when control goes to `getwritabledatabase` I am getting exception – Siva Feb 06 '14 at 06:17

Jim · Answer 4 · 2014-02-06T06:18:22.680

0

When you instantiate StockTable, these two lines are a problem:

Context c1;
Database d1=new Database(c1);

c1 is not initialized.. there is no context in which to create the database. Pass in a valid context to your constructor, or use a "set" method, then instantiate your database for use. Like this:

public StockTable(Context context) {
 c1 = context;
 d1=new Database(c1);
}

And I would replace:

String select="Select StockID from Stocktable";

with:

String select="Select "+  column1 + " from " + tablename;

edited Feb 06 '14 at 06:18

answered Feb 06 '14 at 06:12

Jim

10,172
1
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Thanks for your reply Jim but how to pass a valid context I am a newbie to android, Can you please explain more on this also `Database d1=new Database(***);` at `***` part I am not getting any `getapplicationcontext` or anything like that. – Siva Feb 06 '14 at 06:15
I edited my answer. Also your activity should have this line in onCreate: d=new Database(this); - other answers mention this, but your comment that it is working there leads me to believe that it is OK the way it is, even though it looks wrong... – Jim Feb 06 '14 at 06:20

score 0 · Answer 5 · edited May 23 '17 at 10:29

0

Whenever you are working with the database and helper,

Database database = new Database(this);

You cannot use the class instance as Context until onCreate(). Defer your database and db initialization to onCreate() or later.

Refer these also, to understand it better:

SQlite Database: Unable to find context
nullPointerException for SQLiteOpenHelper.getWritableDatabase(), Android

edited May 23 '17 at 10:29

Community

1
1

answered Feb 06 '14 at 06:18

Pararth

8,114
4
34
51

Getting error while executing getwritabledatabase() in android

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