我知道有关于此主题的几个主题，但我没有找到适合我的解决方案。我应用了一些提示，但错误仍然存在。
这是我得到的错误，尽管我有一个“_id”栏：
java.lang.IllegalArgumentException: column '_id' does not exist
我现在正在解决这个问题，我希望有人可以帮助我。我得到的第一个错误来自“super（context，c，flags）”行;在“GridViewCustomAdapter”中（标记为注释）。
DataSet（SQLiteOpenHelper）：
public class DataSet extends SQLiteOpenHelper {
// Database Version
private static int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "minecraft";
// Items table name
private static final String TABLE_ITEMS = "items";
// Items Table Columns names
public static final String KEY_ID = "_id";
public static final String KEY_MC_ID = "mc_id";
public static final String KEY_NAME = "name";
public static final String KEY_CATEGORY = "category";
public static final String KEY_SUBCATEGORY = "subcategory";
public static final String KEY_URL_EXT = "url_ext";
private static final String[] COLUMNS = { KEY_ID, KEY_MC_ID, KEY_NAME, KEY_CATEGORY, KEY_SUBCATEGORY, KEY_URL_EXT };
public DataSet(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.d("R", "oncreate...");
// SQL statement to create book table
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + " (" +
KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
KEY_MC_ID + " TEXT," +
KEY_NAME + " TEXT," +
KEY_CATEGORY + " TEXT," +
KEY_SUBCATEGORY + " TEXT," +
KEY_URL_EXT + " TEXT )";
// create items table
db.execSQL(CREATE_ITEMS_TABLE);
/*
FileInputStream fis;
fis = getApplicationContext().openFileInput("test.txt");
StringBuilder fileContent = new StringBuilder();
byte[] buffer = new byte[1024];
try {
int n;
while ((n = fis.read(buffer)) != -1) {
fileContent.append(new String(buffer, 0, n));
}
} catch (Exception e) {
}
*/
//Delete
/*SQLiteDatabase dba = this.getWritableDatabase();
Item item = new Item(12, "Diamond Sword", "Combat", null, "C:/Users", "C:/Users/images");
ContentValues values = new ContentValues();
values.put(KEY_MC_ID, item.getMcId()); // get author
values.put(KEY_CATEGORY, item.getCategory());
values.put(KEY_SUBCATEGORY, item.getSubcategory());
values.put(KEY_URL_EXT, item.getUrlExtension());
values.put(KEY_IMAGE_REF, item.getImageRef());
dba.insert(TABLE_ITEMS, null, values);
Cursor cursor = dba.query(TABLE_ITEMS, COLUMNS, KEY_ID, new String[] {"*"}, null, null, null, null);
if (cursor == null) {
Log.d("Tag: ", "Error, nichts gefunden!");
} else {
cursor.moveToFirst();
String p = cursor.getString(2);
Log.d("Tag", p);
}*/
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older items table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_ITEMS);
// create fresh items table
this.onCreate(db);
}
public Cursor getAllItems() {
SQLiteDatabase database = this.getReadableDatabase();
return database.query(TABLE_ITEMS, null, null, null, null, null, null, null);
}
public void addItem(Item item){
// 1. get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// 2. create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put(KEY_MC_ID, item.getMcId()); // get author
values.put(KEY_NAME, item.getName());
values.put(KEY_CATEGORY, item.getCategory());
values.put(KEY_SUBCATEGORY, item.getSubcategory());
values.put(KEY_URL_EXT, item.getUrlExtension());
// 3. insert
//db.insert(TABLE_ITEMS, null, values);
//TEST START
db.insertWithOnConflict(TABLE_ITEMS,null,values,SQLiteDatabase.CONFLICT_REPLACE);
//TEST FINISH
// 4. close
db.close();
}
public void addItemList(List<Item> list) {
int oldVersion = this.getWritableDatabase().getVersion();
onUpgrade(this.getWritableDatabase(), oldVersion, ++oldVersion);
SQLiteDatabase db = this.getWritableDatabase();
db.needUpgrade(12);
Calendar c = Calendar.getInstance();
Date start = c.getTime();
Log.d("Started inserting...",start.toString());
for (Item i : list) {
ContentValues values = new ContentValues();
values.put(KEY_MC_ID, i.getMcId()); // get author
values.put(KEY_NAME, i.getName());
values.put(KEY_CATEGORY, i.getCategory());
values.put(KEY_SUBCATEGORY, i.getSubcategory());
values.put(KEY_URL_EXT, i.getUrlExtension());
//db.insert(TABLE_ITEMS, null, values);
db.insertWithOnConflict(TABLE_ITEMS,null,values,SQLiteDatabase.CONFLICT_IGNORE);
}
Date end = c.getTime();
Log.d("Finished inserting: ", end.toString());
db.close();
}
public Item getItem(String mc_id){
// 1. get reference to readable DB
SQLiteDatabase db = this.getReadableDatabase();
// 2. build query
Cursor cursor =
db.query(TABLE_ITEMS, // a. table
COLUMNS, // b. column names
KEY_MC_ID, // c. selections OLD, FALLS ES FAILT: KEY_ID + " = ?",
new String[] { String.valueOf(mc_id) }, // d. selections args
null, // e. group by
null, // f. having
null, // g. order by
null); // h. limit
// 3. if we got results get the first one
if (cursor.moveToFirst()) {
// 4. build book object
Item item = new Item();
item.setMcId(cursor.getString(1));
item.setName(cursor.getString(2));
item.setCategory(cursor.getString(3));
item.setSubcategory(cursor.getString(4));
item.setUrlExtension(cursor.getString(5));
return item;
}
return null; //Else...
}
public boolean containsItems() {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor =
db.query(TABLE_ITEMS, // a. table
null, // b. column names
null, // c. selections
null, // d. selections args
null, // e. group by
null, // f. having
null, // g. order by
null); // h. limit
if (cursor.getCount() > 0) return true;
else return false;
}
//public Cursor getSpecificItems(String key_mc_id, String key_nameE, String key_cat, String key_subcat, String key_url_ext) {
public Cursor getSpecificItems(String[] selectionArgs) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT " + KEY_SUBCATEGORY + " FROM " + TABLE_ITEMS + " WHERE " + KEY_SUBCATEGORY + " = ?", selectionArgs);
return cursor;
}
}
DatabaseController：
public class DatabaseController {
private Context context;
private DataSet dataset;
public static Resources resources = null;
List<Item> itemList = new ArrayList<Item>();
public DatabaseController(Context context) {
this.context = context;
this.dataset = new DataSet(context);
}
public void readDataAndAddToDatabase() {
try {
resources = context.getResources();
InputStream is = resources.openRawResource(R.raw.database_values);
InputStreamReader isr = new InputStreamReader(is);
BufferedReader reader = new BufferedReader(isr);
String input;
while ((input = reader.readLine()) != null) {
itemList.add(new Item(input));
}
dataset.addItemList(itemList);
} catch (Exception e) {
Log.d("Fehler!!!!!!!!!!!!!!!!!!!!!!!!", "");
e.printStackTrace();
}
}
public Cursor getSpecificItems(String[] selectionArgs) {
return this.dataset.getSpecificItems(selectionArgs);
}
public boolean containsItems() {
return dataset.containsItems();
}
public DataSet getDatabase() {
return this.dataset;
}
public Cursor getAllItems() {
return dataset.getAllItems();
}
}
GridViewCustonAdapter（CursorAdapter）：
public class GridViewCustomAdapter extends CursorAdapter
{
Context context;
private LayoutInflater mInflater;
public GridViewCustomAdapter(Context context, Cursor c, int flags) {
super(context, c, flags); //The Crash seems to start from here...
this.context = context;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView content = (TextView) view.findViewById(R.id.textView);
content.setText(cursor.getString(cursor.getColumnIndex(DataSet.KEY_NAME)));
ImageView image = (ImageView) view.findViewById(R.id.imageView);
image.setImageBitmap(getBitmapFromAsset(cursor.getString(cursor.getColumnIndex(DataSet.KEY_MC_ID + ".png"))));
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
return mInflater.inflate(R.layout.item_layout, parent, false);
}
private Bitmap getBitmapFromAsset(String strName)
{
AssetManager assetManager = context.getAssets();
InputStream istr = null;
try {
istr = assetManager.open(strName);
} catch (IOException e) {
e.printStackTrace();
}
Bitmap bitmap = BitmapFactory.decodeStream(istr);
return bitmap;
}
}
ItemsView（活动）：
public class ItemsView extends Activity {
DatabaseController dbc;
GridView gridView;
GridViewCustomAdapter gridViewCustomAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
// String category = savedInstanceState.getString(getString(R.string.key_category));
// String subcategory = savedInstanceState.getString(getString(R.string.key_subcategory));
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_items_view);
this.dbc = new DatabaseController(this);
Cursor cursor = dbc.getSpecificItems(new String[] { "tools" });
gridView = (GridView)findViewById(R.id.gridViewCustom);
// Create the Custom Adapter Object
gridViewCustomAdapter = new GridViewCustomAdapter(this, cursor, 0);
// Set the Adapter to GridView
gridView.setAdapter(gridViewCustomAdapter);
// Handling touch/click Event on GridView Item
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long arg3) {
String selectedItem;
if(position%2==0)
selectedItem="Facebook" + " @Position: " + position;
else
selectedItem="Twitter" + " @Position: " + position;
Toast.makeText(getApplicationContext(), "Selected Item: " + selectedItem, Toast.LENGTH_SHORT).show();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.items_view, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
activity_items_view.xml（ItemsView - 布局）：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="com.nubage.minepedia.ItemsView">
<GridView
android:id="@+id/gridViewCustom"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="4dp"
android:columnWidth="80dp"
android:gravity="center"
android:numColumns="auto_fit"
android:stretchMode="columnWidth" />
</RelativeLayout>
item_layout.xml（一个简单条目的布局，应该在GridView中从“activity_items_view.xml”多次出现：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="5dp" >
<ImageView
android:id="@+id/imageView"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_marginRight="10dp"
android:src="@drawable/ic_launcher" >
</ImageView>
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:textSize="15sp" >
</TextView>
</LinearLayout>
堆栈跟踪：
08-16 09:42:50.128 914-914/com.nubage.minepedia E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.nubage.minepedia, PID: 914
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nubage.minepedia/com.nubage.minepedia.ItemsView}: java.lang.IllegalArgumentException: column '_id' does not exist
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2255)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
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:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
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.nubage.minepedia.GridViewCustomAdapter.<init>(GridViewCustomAdapter.java:28)
at com.nubage.minepedia.ItemsView.onCreate(ItemsView.java:40)
at android.app.Activity.performCreate(Activity.java:5720)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
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:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
答案 0 :(得分：2)
_id列需要位于游标中，而不仅仅是在表格中！您需要在select语句中包含该列。
...而且，顺便说一下，你实际上并不需要表中的_id列。大多数SQLite表都有一个名为ROWID的隐式列，它是唯一且整数值的。通过更改查询以包含以下内容，您可以非常简单地使现有代码生效：
SELECT ROWID as _id, ...
答案 1 :(得分：1)
游标不包含名为_id的列; getSpecificItems不会返回此列。