android - Getting Error java.lang.IllegalStateException: get field slot from row 0 col -1 failed -

helper class:

package com.deangrobler.myapp;  import java.io.fileoutputstream; import java.io.ioexception; import java.io.inputstream; import java.io.outputstream;  import android.content.context; import android.database.cursor; import android.database.sqlexception; import android.database.sqlite.*;  public class databasehelper extends sqliteopenhelper{  //the android's default system path of application database. private static string db_path = "/data/data/com.deangrobler.chumperoo/databases/";  private static string db_name = "chumperoodb.db";  private sqlitedatabase mydatabase;   private final context mycontext;  /**  * constructor  * takes , keeps reference of passed context in order access application assets , resources.  * @param context  */ public databasehelper(context context) {      super(context, db_name, null, 1);     this.mycontext = context; }     /**  * creates empty database on system , rewrites own database.  * */ public void createdatabase() throws ioexception{      boolean dbexist = checkdatabase();      if(dbexist){         //do nothing - database exist     }else{          //by calling method , empty database created default system path            //of application gonna able overwrite database our database.         this.getreadabledatabase();          try {              copydatabase();          } catch (ioexception e) {              throw new error("error copying database: " + e.getstacktrace());          }     }  }  /**  * check if database exist avoid re-copying file each time open application.  * @return true if exists, false if doesn't  */ private boolean checkdatabase(){      sqlitedatabase checkdb = null;      try{         string mypath = db_path + db_name;         checkdb = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readonly);      }catch(sqliteexception e){          //database does't exist yet.      }      if(checkdb != null){          checkdb.close();      }      return checkdb != null ? true : false; }  /**  * copies database local assets-folder created empty database in  * system folder, can accessed , handled.  * done transfering bytestream.  * */ private void copydatabase() throws ioexception{      //open local db input stream     inputstream myinput = mycontext.getassets().open(db_name);      // path created empty db     string outfilename = db_path + db_name;      //open empty db output stream     outputstream myoutput = new fileoutputstream(outfilename);      //transfer bytes inputfile outputfile     byte[] buffer = new byte[1024];     int length;     while ((length = myinput.read(buffer))>0){         myoutput.write(buffer, 0, length);     }      //close streams     myoutput.flush();     myoutput.close();     myinput.close();  }  public void opendatabase() throws sqlexception{      //open database     string mypath = db_path + db_name;     mydatabase = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readwrite);  }  @override public synchronized void close() {          if(mydatabase != null)             mydatabase.close();          super.close();  }  @override public void oncreate(sqlitedatabase db) {  }  @override public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {  }  //queries database public cursor querydatabase(string table, string[] columns, string selection){      return mydatabase.query(table, columns, selection, null, null, null, null);  }  } 

using in main.java so:

databasehelper mydbhelper = new databasehelper(this);      try {         mydbhelper.createdatabase();     } catch (ioexception ioe) {         throw new error("unable create database");      }      try {         mydbhelper.opendatabase();     }catch(sqlexception sqle){         throw sqle;     }      //get cursor , print out data     cursor returnedcur = mydbhelper.querydatabase("expenses", new string[]{"name","amount"}, null);     if (returnedcur.movetofirst()){         do{             string data = returnedcur.getstring(returnedcur.getcolumnindex("data"));             system.out.println("returned data: "+data);          }while(returnedcur.movetonext());     }     returnedcur.close(); 

and finaly entire log:

> 06-05 13:28:35.885: e/cursorwindow(733): bad request field slot 0,-1. numrows = 1, numcolumns = 2 06-05 13:28:35.885: d/androidruntime(733): shutting down vm 06-05 13:28:35.885: w/dalvikvm(733): threadid=1: thread exiting uncaught exception (group=0x40015560) 06-05 13:28:35.904: e/androidruntime(733): fatal exception: main 06-05 13:28:35.904: e/androidruntime(733): **java.lang.runtimeexception: unable start activity componentinfo{com.deangrobler.chumperoo/com.deangrobler.chumperoo.main}: java.lang.illegalstateexception: field slot row 0 col -1 failed** 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1622) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread.handlelaunchactivity(activitythread.java:1638) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread.access$1500(activitythread.java:117) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread$h.handlemessage(activitythread.java:928) 06-05 13:28:35.904: e/androidruntime(733):  @ android.os.handler.dispatchmessage(handler.java:99) 06-05 13:28:35.904: e/androidruntime(733):  @ android.os.looper.loop(looper.java:123) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread.main(activitythread.java:3647) 06-05 13:28:35.904: e/androidruntime(733):  @ java.lang.reflect.method.invokenative(native method) 06-05 13:28:35.904: e/androidruntime(733):  @ java.lang.reflect.method.invoke(method.java:507) 06-05 13:28:35.904: e/androidruntime(733):  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:839) 06-05 13:28:35.904: e/androidruntime(733):  @ com.android.internal.os.zygoteinit.main(zygoteinit.java:597) 06-05 13:28:35.904: e/androidruntime(733):  @ dalvik.system.nativestart.main(native method) 06-05 13:28:35.904: e/androidruntime(733): caused by: java.lang.illegalstateexception: field slot row 0 col -1 failed 06-05 13:28:35.904: e/androidruntime(733):  @ android.database.cursorwindow.getstring_native(native method) 06-05 13:28:35.904: e/androidruntime(733):  @ android.database.cursorwindow.getstring(cursorwindow.java:329) 06-05 13:28:35.904: e/androidruntime(733):  @ android.database.abstractwindowedcursor.getstring(abstractwindowedcursor.java:49) 06-05 13:28:35.904: e/androidruntime(733):  @ com.deangrobler.chumperoo.main.oncreate(main.java:55) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1047) 06-05 13:28:35.904: e/androidruntime(733):  @ android.app.activitythread.performlaunchactivity(activitythread.java:1586) 06-05 13:28:35.904: e/androidruntime(733):  ... 11 more 06-05 13:28:53.264: i/process(733): sending signal. pid: 733 sig: 9 

no idea why happening, i've been googling half day , nothing helping me sort out :-(

new string[]{"name","amount"} 

you asking "data" field cant found field name "data" in db. can try

string name = returnedcur.getstring(returnedcur.getcolumnindex("name"));