Question

我的应用程序在启动时将16条记录插入数据库。但是当我输出这些记录时，1条记录（Union Restaurant）正在重复16次。 RLocationDatabase.java创建数据库。 RDatabaseModel.java是数据库内容的结构。 MainActivity.java执行应用程序并插入记录。

RLocationDatabase.java

public class RLocationDatabase extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "RGeoDbase";

public static final String TABLE_RG = "RGeoDbase";
public static final String PR_KEY = "ID";
public static final String R_ID = "RestaurantID";
public static final String R_Name = "Name";
public static final String R_Latitude = "Latitude";
public static final String R_Longitude = "Longitude";

public static final String [] COLUMNS = {PR_KEY,R_ID,R_Name,R_Latitude,R_Longitude};


public RLocationDatabase(Context context){
    super(context, DATABASE_NAME, null, DATABASE_VERSION);  
}

@Override
public void onCreate(SQLiteDatabase data){

    String CREATE_DB = "CREATE TABLE RGeoDbase ( " + "ID VARCHAR PRIMARY KEY, " + "Name TEXT, "
                        + "Latitude DECIMAL(10,8), " + "Longitude DECIMAL(11,8) )";

    data.execSQL(CREATE_DB);
}

@Override
public void onUpgrade(SQLiteDatabase data, int oldV, int newV){

    data.execSQL("DROP TABLE IF EXISTS RGeoDbase");

    this.onCreate(data);
}

public boolean insertRecord(String name, double latitude, double longitude){
    SQLiteDatabase dbase = this.getWritableDatabase();
    ContentValues values = new ContentValues();

    //values.put(R_ID, r_id);
    values.put(R_Name, name);
    values.put(R_Latitude, latitude);
    values.put(R_Longitude, longitude);

    dbase.insert(TABLE_RG, null, values);
    return true;
}
/*
public Cursor getData(String id){
    SQLiteDatabase dbase = this.getWritableDatabase();
    Cursor cursor = dbase.rawQuery("SELECT * FROM RGeoDbase WHERE Restaurant_ID="+id+"", null);
    return cursor;
}*/

@SuppressWarnings("rawtypes")
public ArrayList<RDatabaseModel> getAllData(){
    RDatabaseModel model = new RDatabaseModel();
    ArrayList<RDatabaseModel> list = new ArrayList<RDatabaseModel>();
    SQLiteDatabase dbase = this.getReadableDatabase();

    Cursor cursor = dbase.rawQuery("SELECT * FROM RGeoDbase", null);
    cursor.moveToFirst();
    while(!cursor.isAfterLast()){
        //model.setRestaurantID(cursor.getString(cursor.getColumnIndex(R_ID)));
        model.setName(cursor.getString(cursor.getColumnIndex(R_Name)));
        model.setLatitude(cursor.getDouble(cursor.getColumnIndex(R_Latitude)));
        model.setLongitude(cursor.getDouble(cursor.getColumnIndex(R_Longitude)));

        list.add(model);
        cursor.moveToNext();
    }
    return list;
}

public void close(){
    this.close();
}
}

RDatabaseModel.java

public class RDatabaseModel {

private String name;
private double latitude;
private double longitude;

public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public double getLatitude() {
    return latitude;
}
public void setLatitude(double latitude) {
    this.latitude = latitude;
}
public double getLongitude() {
    return longitude;
}
public void setLongitude(double longitude) {
    this.longitude = longitude;
}
}

MainActivity.java

public class MainActivity extends Activity {
public static RLocationDatabase myDatabase;

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        myDatabase = new RLocationDatabase(this);

        buildDatabase();
        setContentView(R.layout.activity_main);

ArrayList<RDatabaseModel> a = myDatabase.getAllData();
        RDatabaseModel rd;
        for(int i=0; i<a.size(); i++){
            rd = a.get(i);
            System.out.println(rd.getName());
        }

    }

public void buildDatabase(){

        if(!myDatabase.insertRecord("Bijas Vegetarian", 22.28416252, 114.13412900)){
            Log.v("1", "error inserting data #1"); 
        }
        myDatabase.insertRecord("Delifrance", 22.28328514, 114.13483800);
        myDatabase.insertRecord("Ebeneezer's Kebabs and Pizzeria", 22.28362400, 114.13973600);
        myDatabase.insertRecord("Bay View Restaurant", 22.26952800, 114.12982000);
        myDatabase.insertRecord("C.C.Canteen", 22.28003600, 114.13058000);
        myDatabase.insertRecord("Cafe 330", 22.28279200, 114.13907500);
        myDatabase.insertRecord("Fong Shu Chen Amenities Centre Restaurant", 22.28383400, 114.13974600);
        myDatabase.insertRecord("FRU:YO Factory", 22.28270600, 114.13874000);
        myDatabase.insertRecord("Garden Patio", 22.26732000, 114.12837100);
        myDatabase.insertRecord("Groove Cafe", 22.28312300, 114.13485300);
        if(!myDatabase.insertRecord("Ho Tim Hall Restaurant", 22.28406700, 114.13283700)){
            System.out.println("error inserting data #11"); 
        }
        myDatabase.insertRecord("Maxim's Food 2", 22.28309900, 114.13949100);
        myDatabase.insertRecord("Pacific Coffee Company", 22.28363500, 114.13966600);
        myDatabase.insertRecord("Starbucks Coffee (Main Campus)", 22.28312100, 114.13803300);
        if(!myDatabase.insertRecord("Subway Sandwiches", 22.28264100, 114.13850600)){
            Log.v("15","error inserting #15");
        }
        myDatabase.insertRecord("Union Restaurant", 22.28315100, 114.13590700);
    }
}

Answer 1

可能需要直接在while循环中创建数据库模型对象。

while(!cursor.isAfterLast()){
    RDatabaseModel model = new RDatabaseModel(); // here
    model.setName(cursor.getString(cursor.getColumnIndex(R_Name)));
    model.setLatitude(cursor.getDouble(cursor.getColumnIndex(R_Latitude)));
    model.setLongitude(cursor.getDouble(cursor.getColumnIndex(R_Longitude)));

    list.add(model);
    cursor.moveToNext();
}

Answer 2

将ID设为id integer primary key autoincrement

SQLite数据库仅插入最后一条记录 - Android

2 个答案: