E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.bestbuy.mytry, PID: 32644
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bestbuy.mytry/com.example.bestbuy.mytry.DisplayActivity}: java.lang.IllegalArgumentException: column '_id' does not exist
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:902)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:697)
Caused by: java.lang.IllegalArgumentException: column '_id' does not exist
at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:303)
at android.widget.CursorAdapter.init(CursorAdapter.java:172)
at android.widget.CursorAdapter.<init>(CursorAdapter.java:149)
at com.example.bestbuy.mytry.CustomAdapter.<init>(CustomAdapter.java:19)
at com.example.bestbuy.mytry.DisplayActivity.onCreate(DisplayActivity.java:18)
at android.app.Activity.performCreate(Activity.java:6033)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
This exception is arising when i retrieve data from sqlitedatabase and displaying it in ListView. I am not able to interpret this. please help in understanding it and what this actually mean in context with my application. If you want some more data let me know. thank you
This is my sqlitedatabase code-
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME="AppDB";
public static final int DATABASE_VERSION=1;
public static final String TABLE_NAME="Users";
public static final String Column1="id";
public static final String Column2="task";
public static final String Column3="ddate";
public static final String Query="CREATE TABLE "+TABLE_NAME+"("+Column1+" INTEGER PRIMARY KEY AUTOINCREMENT,"+Column2+" TEXT NOT NULL,"+Column3+" TEXT NOT NULL)";
public DatabaseHelper(Context context) {
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(Query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public boolean insertValues(String task,String datee) {
SQLiteDatabase db=this.getWritableDatabase();
ContentValues values=new ContentValues();
values.put(Column2,task);
values.put(Column3,datee);
long rows=db.insertOrThrow(TABLE_NAME,null,values);
if(rows>0){
return true;
}
else
return false;
}
public Cursor retrieveValues() {
SQLiteDatabase db=this.getWritableDatabase();
Cursor cursor=db.rawQuery("SELECT * FROM Users",null);
return cursor;
}
This is my customAdapter code:
public class CustomAdapter extends CursorAdapter {
TextView task,daate;
public CustomAdapter(Context context, Cursor cursor) {
super(context, cursor, 0);
}
// The newView method is used to inflate a new view and return it,
// you don't bind any data to the view at this point.
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return LayoutInflater.from(context).inflate(R.layout.adapter, parent, false);
}
// The bindView method is used to bind all data to a given view
// such as setting the text on a TextView.
@Override
public void bindView(View view, Context context, Cursor cursor) {
// Find fields to populate in inflated template
task=(TextView)view.findViewById(R.id.dynamicTask);
daate=(TextView)view.findViewById(R.id.dynamicDate);
String Task=cursor.getString(cursor.getColumnIndex("task"));
String Daate=cursor.getString(cursor.getColumnIndex("ddate"));
task.setText(Task);
daate.setText(Daate);
}
}
And this is my DisplayActivity code:
public class DisplayActivity extends AppCompatActivity {
ListView tasklist;
DatabaseHelper db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show);
tasklist=(ListView)findViewById(R.id.taskList);
db=new DatabaseHelper(this);
Cursor cursor=db.retrieveValues();
CustomAdapter todoadapter=new CustomAdapter(this,cursor);
tasklist.setAdapter(todoadapter);
}
}
