_ID不存在
_ID不存在
提问于 2011-10-11 07:03:34
我试图从幻灯片bbdd中获取数据并将其显示在列表视图中，但我遇到了错误。
public class DataBaseHelper extends SQLiteOpenHelper{
private static String DB_PATH = "/data/data/com.rbrlnx.lugares/databases/";
private static final String DATABASE_NAME="db.db";
SQLiteDatabase db;
String CREATE_TABLE = "CREATE TABLE IF NOT EXISTS lugares (" +
" _id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"nombre text," +
"descripcion text,"+
"latitud real," +
"longitud real," +
"foto String);";
/*Primero se crea constructor, funcion onCreate, onUpgrade,Abrir y Cerrar*/
public DataBaseHelper(Context context){
super(context,DATABASE_NAME,null,1);
}
public void onCreate(SQLiteDatabase db){
try {
openDataBase();
db.execSQL(CREATE_TABLE);
} catch (Exception e) {
// handle exception
}
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DATABASE_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
public void close(){
db.close();
}
/*Despues metodos para añadir y obtener datos*/
public long addNombre(String nombre){
ContentValues cv = new ContentValues();
cv.put("nombre", nombre);
return db.insert("lugares", null, cv);
}
public long addDescripcion(String descripcion){
ContentValues cv = new ContentValues();
cv.put("descripcion", descripcion);
return db.insert("lugares", null, cv);
}
public long addLatitud(double latitud){
ContentValues cv = new ContentValues();
cv.put("latitud", latitud);
return db.insert("lugares", null, cv);
}
public long addLongitud(double longitud){
ContentValues cv = new ContentValues();
cv.put("longitud", longitud);
return db.insert("lugares", null, cv);
}
public long addFoto(String foto) {
ContentValues cv = new ContentValues();
cv.put("foto", foto);
return db.insert("lugares", null, cv);
}
public Cursor getNombres(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor respuesta = db.rawQuery("select nombre from lugares", null);
return respuesta;
}
}和
public class listatab extends ListActivity{
Context context;
ListView listanombres;
DataBaseHelper ayudabbdd;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
DataBaseHelper ayudabbdd = new DataBaseHelper(this);
Cursor nombresC;
nombresC = (Cursor) ayudabbdd.getNombres();
startManagingCursor(nombresC);
if(nombresC!=null){
ListAdapter adapter = new SimpleCursorAdapter(this, R.layout.listatab, nombresC, new String[] { "nombre" }, new int[] { R.id.lista });
this.setListAdapter(adapter);
this.getListView().setTextFilterEnabled(true);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if (ayudabbdd != null) {
ayudabbdd.close();
}
}
}log cat向我显示了以下错误：
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.rbrlnx.lugares/com.rbrlnx.lugares.listatab}: java.lang.IllegalArgumentException: column '_id' does not exist
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.app.ActivityThread.startActivityNow(ActivityThread.java:1487)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:654)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.widget.TabHost.setCurrentTab(TabHost.java:326)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:132)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:456)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.view.View.performClick(View.java:2485)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.view.View$PerformClick.run(View.java:9080)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.os.Handler.handleCallback(Handler.java:587)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.os.Handler.dispatchMessage(Handler.java:92)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.os.Looper.loop(Looper.java:130)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at android.app.ActivityThread.main(ActivityThread.java:3683)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at java.lang.reflect.Method.invokeNative(Native Method)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at java.lang.reflect.Method.invoke(Method.java:507)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): at dalvik.system.NativeStart.main(Native Method)
10-11 00:55:49.930: ERROR/AndroidRuntime(32392): Caused by: java.lang.IllegalArgumentException: column '_id' does not exist回答 5
Stack Overflow用户
发布于 2011-10-11 07:39:02
您的openDataBase()方法非常错误。您不应该提供数据库的路径。系统将为您创建数据库，并在onCreate()方法中将其传递给您。如果删除openDataBase()方法并且不从onCreate()调用它，并在onCreate()中设置this.db = db，则可以克服此错误。
有关在Android中使用数据库的更多帮助，请参阅此Android Database Tutorial。祝好运!
Stack Overflow用户
发布于 2011-10-11 15:12:00
我认为_id列也必须被选中。
Cursor respuesta = db.rawQuery("select _id，nombre from lugares"，null)；
Stack Overflow用户
发布于 2011-10-11 07:18:54
在没有更多信息的情况下(我也不是Android专家)，我怀疑您的表要么不存在，要么存在但没有_id列。您使用的是CREATE TABLE IF NOT EXISTS，如果表-可能具有不同的列-已经存在，则会导致create语句不被执行。
您没有记录您的异常，因此该语句实际上可能会抛出一个被忽略的异常。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/7719657
复制相关文章
相似问题
腾讯云开发者
