安卓 studio 2.2中的java Sqlite
我在函数getfood的DESC中编写查询get error时出错。这是我的例外
例外情况：
崩溃开始
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.app.caloriescounter.admin.caloriescounter, PID: 2759
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.app.caloriescounter.admin.caloriescounter/com.app.caloriesc
ounter.admin.caloriescounter.Main2Activity}:
java.lang.IllegalArgumentException: **invalid LIMIT clauses: DESC**
at
安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at
安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at 安卓.app.ActivityThread.-wrap11(ActivityThread.java)
at
安卓.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at 安卓.os.Handler.dispatchMessage(Handler.java:102)
at 安卓.os.Looper.loop(Looper.java:148)
at
安卓.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at
com.安卓.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at
com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.IllegalArgumentException: invalid LIMIT clauses: DESC
at
安卓.database.sqlite.SQLiteQueryBuilder.buildQueryString(SQLiteQueryBuilde
r.java:209)
at
安卓.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1160)
at
安卓.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1034)
at
安卓.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1240)
at
data.Databasehandler.getfood(Databasehandler.java:86)
at
com.app.caloriescounter.admin.caloriescounter.Main2Activity.refreshdata(Main2Activity.java:38)
at com.app.caloriescounter.admin.caloriescounter.Main2Activity.onCreate(Main2Activity.java:32)
at 安卓.app.Activity.performCreate(Activity.java:6237)
at
安卓.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at
安卓.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at
安卓.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at 安卓.app.ActivityThread.-
wrap11(ActivityThread.java)
at
安卓.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at
安卓.os.Handler.dispatchMessage(Handler.java:102)
at 安卓.os.Looper.loop(Looper.java:148)
at
安卓.app.ActivityThread.main(ActivityThread.java:5417)
这是我的Databasehandler类的源代码
package data;
import 安卓.content.ContentValues;
import 安卓.content.Context;
import 安卓.database.Cursor;
import 安卓.database.sqlite.SQLiteDatabase;
import 安卓.database.sqlite.SQLiteOpenHelper;
import 安卓.util.Log;
import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
import model.Food;
/**
* Created by Admin on 9/10/2016.
*/
public class Databasehandler extends SQLiteOpenHelper {
private static final String LOGCAT = null;
private final ArrayList<Food> foodArrayList=new ArrayList<>();
public Databasehandler(Context context) {
super(context,Constsnts.databasename,null,Constsnts.databaseversion);
Log.d(LOGCAT,"Database Created");
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
String Crete_Table="CREATE TABLE "+ Constsnts.food_table+" ( " +
Constsnts.KeyId +"INTEGER PRIMARY KEY, " + Constsnts.food_name +"TEXT, "
+Constsnts.foodcalories +"INT , "+Constsnts.datename +"LONG );";
sqLiteDatabase.execSQL(Crete_Table);
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
sqLiteDatabase.execSQL("DROP TABLE IF EXISTS "+Constsnts.food_table);
//new one
onCreate(sqLiteDatabase);
}
//item all
public int getTotalitem(){
int totalitem=0;
String query=" SELECT * FROM "+Constsnts.food_table;
SQLiteDatabase db=this.getReadableDatabase();
Cursor cursor=db.rawQuery(query,null);
totalitem=cursor.getCount();
cursor.close();
return totalitem;
}
public int Caloriesall(){
int calories=0;
String query="SELECT SUM ( "+Constsnts.foodcalories +")"+"FROM
"+Constsnts.food_table;
SQLiteDatabase db=this.getReadableDatabase();
Cursor cursor=db.rawQuery(query,null);
if(cursor.moveToNext()){
calories=cursor.getInt(0);
}
cursor.close();
db.close();
return calories;
}
//deletefood
public void deletefood(int id){
SQLiteDatabase db=this.getWritableDatabase();
db.delete(Constsnts.food_table,Constsnts.KeyId+" =? ",new String[]
{String.valueOf(id)});
db.close();
}
//add food
public void addfood(Food food){
SQLiteDatabase db=this.getWritableDatabase();
ContentValues values=new ContentValues();
values.put(Constsnts.food_name,food.getFoodname());
values.put(Constsnts.foodcalories,food.getCaleries());
values.put(Constsnts.datename,System.currentTimeMillis());
db.insert(Constsnts.food_table,null,values);
Log.v("Added food item","yess");
db.close();
}
//get all food
public ArrayList<Food> getfood(){
foodArrayList.clear();
SQLiteDatabase db=this.getReadableDatabase();
Cursor cursor=db.query(Constsnts.food_table,new String[]
{Constsnts.KeyId,Constsnts.databasename,
Constsnts.foodcalories,Constsnts.datename},null,null,null,null,Constsnts.datename," DESC ");
if(cursor.moveToFirst()){
do {
Food food=new Food();
food.setFoodname(cursor.getString(cursor.getColumnIndex(Constsnts.food_name)));
food.setCaleries(cursor.getInt(cursor.getColumnIndex(Constsnts.foodcalories)));
food.setFoodid(cursor.getInt(cursor.getColumnIndex(Constsnts.KeyId)));
DateFormat dateFormat=DateFormat.getDateInstance();
String data=dateFormat.format(new
Date(cursor.getLong(cursor.getColumnIndex(Constsnts.datename))).getTime());
food.setRecorddate(data);
foodArrayList.add(food);
}while(cursor.moveToNext());
}
cursor.close();
db.close();
return foodArrayList;
}
}
提前谢谢
共 (0) 个答案