android - App Crashes On Startup Due To java.lang.IllegalArgumentException: column '_id' does not exist -


whenever start app, java.lang.illegalargumentexception: column '_id' not exist error in logcat. have created column '_id', still throws this. here main .java:

package com.gantt.shoppinglist;  import android.app.dialog; import android.app.listactivity; import android.database.cursor; import android.os.bundle; import android.view.view; import android.view.view.onclicklistener; import android.widget.button; import android.widget.edittext; import android.widget.listview; import android.widget.simplecursoradapter;  public class shoppinglist extends listactivity {      private datahelper datahelper;     /** called when activity first created. */     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.main);         datahelper = new datahelper(this);          cursor c = (cursor) datahelper.selectall();         long id = c.getlong(c.getcolumnindex("_id"));         startmanagingcursor(c);          listview lv = (listview) findviewbyid(android.r.id.list);          string[] = new string[] { com.gantt.shoppinglist.datahelper.getdatabasename() };         int[] = new int[] { android.r.id.text1 };          simplecursoradapter adapter = new simplecursoradapter(this,                 android.r.layout.simple_list_item_1, c, from, to);                lv.setadapter(adapter);          button button1main = (button) findviewbyid(r.id.add);         button1main.setonclicklistener(new onclicklistener()  {             @override             public void onclick(view v)  {             final dialog additem = new dialog(shoppinglist.this);             additem.setcontentview(r.layout.maindialog);             final edittext et = (edittext)additem.findviewbyid(r.id.edittext);             additem.settitle("type item");             additem.setcancelable(true);             et.sethint("type name of item...");              button button = (button) additem.findviewbyid(r.id.cancel);             button.setonclicklistener(new onclicklistener()  {                 @override                 public void onclick(view v)  {                     additem.dismiss();                 }             });             additem.show();              button ok = (button) additem.findviewbyid(r.id.ok);             ok.setonclicklistener(new onclicklistener() {                 @override                 public void onclick(view v) {                     final string text = et.gettext().tostring();                     additem.dismiss();                     et.settext("");                 }             });        }         });     } } 

here datahelper class:

package com.gantt.shoppinglist;  import java.util.arraylist; import java.util.list;  import android.content.context; import android.database.cursor; import android.database.sqlite.sqlitedatabase; import android.database.sqlite.sqliteopenhelper; import android.database.sqlite.sqlitestatement; import android.util.log;  public class datahelper {         private static final string database_name = "items.db";        private static final int database_version = 1;        private static final string table_name = "table1";        public static final string key_rowid = "_id";         private context context;        private sqlitedatabase db;         private sqlitestatement insertstmt;        private static final string insert = "insert "            + table_name + "(name) values (?)";         public datahelper(context context) {           this.context = context;           openhelper openhelper = new openhelper(this.context);           this.db = openhelper.getwritabledatabase();           this.insertstmt = this.db.compilestatement(insert);        }         public long insert(string name) {           this.insertstmt.bindstring(1, name);           return this.insertstmt.executeinsert();        }         public void deleteall() {           this.db.delete(table_name, null, null);        }         public cursor selectall() {           list<string> list = new arraylist<string>();           cursor cursor = this.db.query(table_name, new string[] { "name" },              null, null, null, null, "name desc");           if (cursor.movetofirst()) {              {                 list.add(cursor.getstring(0));               } while (cursor.movetonext());           }           if (cursor != null && !cursor.isclosed()) {              cursor.close();           }           return cursor;        }         public static string getdatabasename() {         return database_name;     }      private static class openhelper extends sqliteopenhelper {            openhelper(context context) {              super(context, getdatabasename(), null, database_version);           }            @override           public void oncreate(sqlitedatabase db) {               db.execsql("create table " + table_name + "(id integer primary key, name text");            }            @override           public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {              log.w("example", "upgrading database, drop tables , recreate.");              db.execsql("drop table if exists " + table_name);              oncreate(db);           }        }     } 

i had similar issue - think it's case of having 'select' (or 'select as') called _id because simplecursoradapter needs it.

from documentation:

handling content uri ids

by convention, providers offer access single row in table accepting content uri id value row @ end of uri. convention, providers match id value table's _id column, , perform requested access against row matches.

this convention facilitates common design pattern apps accessing provider. app query against provider , displays resulting cursor in listview using cursoradapter. definition of cursoradapter requires 1 of columns in cursor _id.

in case, have autonumber column in table called 'oid' altered select command (for example)...

select oid _id, name, number mytable 

this cured problem me.

edit show more extensive code...

@override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.channel_selector);      gridview channel_selector_grid = (gridview) findviewbyid(r.id.channel_grid);     sca = getguideadapter();     channel_selector_grid.setadapter(sca); }  public simplecursoradapter getguideadapter() {     simplecursoradapter adapter = null;     sqlitedatabase db = sqlitedatabasehelper.getreadabledatabase();     cursor cursor = db.rawquery("select distinct oid _id, name, number chan_table order number", null);     if (cursor.movetofirst()) {         string[] columnnames = { "name" };         int[] resids = { r.id.channel_name };         adapter = new simplecursoradapter(this, r.layout.channel_selector_item, cursor, columnnames, resids);     }     return adapter;  } 

Comments

Popular posts from this blog

python - Healpy: From Data to Healpix map -

c - Bitwise operation with (signed) enum value -

xslt - Unnest parent nodes by child node -