SQLite表记录空值

Question

我想从android GPS传感器拉纬度和经度，并将它们写入本地sqlite数据库文件中的列。但是，我似乎无法弄清楚为什么这些值不是正确的纬度和经度。

DatabaseHandler.java

import java.util.ArrayList; 
import java.util.List; 

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.util.Log; 


`public class DatabaseHandler extends SQLiteOpenHelper { 

// All static variables 
    // Database version 
    private static final int DATABASE_VERSION = 1; 

    // Database name 
    private static final String DATABASE_NAME = "Cordinates Manager"; 

    // Coordinates Table name 
    private static final String TABLE_CORDINATES = "cordinates"; 

    // Coordinates Table Column titles 
    private static final String KEY_ID = "ID"; 
    private static final String KEY_LAT = "LAT"; 
    private static final String KEY_LNG = "LNG"; 

    public String latitudeField; 
    public String longitudeField; 

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

    // Creating Table 
    @Override 
    public void onCreate(SQLiteDatabase db) { 
     String CREATE_CORDINATES_TABLE = "CREATE TABLE " + TABLE_CORDINATES + "(" 
       + KEY_ID + "INTEGER PRIMARY KEY, " + KEY_LAT + //" TEXT," 
       KEY_LNG + ")"; 

     // create table 
     db.execSQL(CREATE_CORDINATES_TABLE); 
    } 

    // Upgrading database 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // Drop older table if existed 
     db.execSQL("DROP TABLE IF EXISTED" + TABLE_CORDINATES); 

     // Create table again 
     this.onCreate(db); 
    } 

    //Adding new Coordinate 
    public void addCordinate(Cordinates cordinate) { 
     // Print to the log cat 
     Log.println(Log.ASSERT, "addCordinate", cordinate.toString()); 
     // 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_LAT, cordinate.getLat()); // Coordinates Lat 
     values.put(KEY_LNG, cordinate.getLng()); // Coordinates Lng 

     // 3. Inserting a Row 
     db.insert(TABLE_CORDINATES, null, values); 
     // 4. Close the database 
     db.close(); // close database connection 
    } 

    // Getting Single Cordinate Row 
    Cordinates getCordinates(int id) { 
     // 1. get reference to readable DB 
     SQLiteDatabase db = this.getReadableDatabase(); 

     // 2. Build query 
     Cursor cursor = db.query(TABLE_CORDINATES,   // a. table 
       new String[] { KEY_ID, KEY_LAT, KEY_LNG }, // b. column names 
       KEY_ID + "=?",        // c. selections 
       new String[] {String.valueOf(id) },   // d. selection args 
       null,          // e. group by 
       null,          // f. having 
       null,          // g. order by 
       null);          // h. limit 

     // 3. if we get results, get the first one 
     if(cursor != null) 
      cursor.moveToFirst(); 

     // 4. build cordinate object 
     Cordinates cordinate = new Cordinates(); 

     // Print to the log cat 
     Log.println(Log.ASSERT,"getCordinates("+id+")", cordinate.toString()); 
     // 5. return cordinates 
     return cordinate; 
    } 

    // Getting All Cordinates 
    public List<Cordinates> getAllCordinates() { 
     List<Cordinates> cordinateList = new ArrayList<Cordinates>(); 
     // 1. Build the query for Select All 
     String selectQuery = "SELECT * FROM * " + TABLE_CORDINATES; 

     // 2. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 
     Cursor cursor = db.rawQuery(selectQuery, null); 


     // 3. Looping through all rows and adding to list 
     if (cursor.moveToFirst()) { 
      do { 
       Cordinates cordinates = new Cordinates(); 
       cordinates.setID(Integer.parseInt(cursor.getString(0))); 
       cordinates.setLat(cursor.getLong(1)); 
       cordinates.setLng(cursor.getLong(2)); 

       // Adding Cordinate to list 
       cordinateList.add(cordinates); 
      } while (cursor.moveToNext()); 
     } 

     Log.println(Log.ASSERT,"getAllCordinates()", cordinateList.toString()); 
     // return the cordinate list 
     return cordinateList; 
    } 

    /* for every new row, update single cordinate row 
    *  'Listen for cordinate values* 
    * if !newRow == false NEW ROOWWWW!! 
    * Create a new value object 
    */ 
    public int updateCordinate(Cordinates cordinate) { 
     SQLiteDatabase db = this.getWritableDatabase(); 

     ContentValues value = new ContentValues(); 
     value.put(KEY_LAT, cordinate.getLat()); // get latitude 
     value.put(KEY_LNG, cordinate.getLng()); // get longitude 

     // Updating row 
     return db.update(TABLE_CORDINATES, value, KEY_ID + " = ?", 
       new String[] { String.valueOf(cordinate.getID())}); 
    } 

    // Deleting a single Coordinate 
    public void deleteCordinate(Cordinates cordinate) { 
     // 1. get reference to writable DB 
     SQLiteDatabase db = this.getWritableDatabase(); 

     // 2. delete 
     db.delete(TABLE_CORDINATES, KEY_ID + "=?", 
       new String[] {String.valueOf(cordinate.getID()) }); 

     // 3. Close 
     db.close(); 
     Log.println(Log.ASSERT, "deleteCordinate", cordinate.toString()); 
    } 

    // Getting Cordinate total count 
    public int getCordinatesCount() { 
     String countQuery = "SELECT * FROM " + TABLE_CORDINATES; 
     SQLiteDatabase db = this.getReadableDatabase(); 
     Cursor cursor = db.rawQuery(countQuery, null); 
     cursor.close(); 

     Log.println(Log.ASSERT, "getcCordinatesCount()", countQuery.toString()); 

     // return count 
     return cursor.getCount(); 
    } 
} 

Cordinates.java

public class Cordinates { 

    // private variables 
    int _id; 
    float _latValue; 
    float _lngValue; 

    // Empty Constructor 
    public Cordinates() { 

    } 

    // constructor 
    public Cordinates(int id, float latValue, float lngValue) { 
     this._id = id; 
     this._latValue = latValue; 
     this._lngValue = lngValue; 
    } 
    /* GETTERS for id, latitude, longitude 
    * Will try to add the import for time later... 
    */ 

    // getting ID 
    public int getID() { 
     return this._id; 
    } 
    // getting latitude 
    public float getLat() { 
     return this._latValue; 
    } 
    // getting longitude 
    public float getLng() { 
     return this._lngValue; 
    } 

    /* SETTERS for id, latitude, longitude 
    * Will try to add the import for time later... 
    */ 
    public void setID(int id) { 
     this._id = id; 
    } 

    // setting latitude 
    public void setLat(long latValue) { 
     this._latValue = latValue; 
    } 

    // setting longitude 
    public void setLng(long lngValue) { 
     this._lngValue = lngValue; 
    } 
} 

MyLocation.java

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.os.Handler; 
import android.provider.Settings; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.util.Log; 
import com.xxx.DatabaseHandler; 

public class MyLocation extends Activity implements LocationListener { 

     private Handler handler = null; 
     private TextView latituteField = null; 
     private TextView longitudeField = null; 
     private double lat = 0; 
     private double lng = 0; 
     DatabaseHandler db = null; 

     @Override 
     protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     Log.println(Log.ASSERT, "MyLocation.java", "App Started ~^*~^*~^*~^*~^*~^*~^*~^*~^*~^*~^*~^*"); 
     setContentView(R.layout.activity_main); 

     // get db 
     db = new DatabaseHandler(getApplicationContext()); 

     // Handler will post to UI thread 
     handler = new Handler(); 

     // normal stuff 
     latituteField = (TextView) findViewById(R.id.latTextView); 
     longitudeField = (TextView) findViewById(R.id.lngTextView); 

     LocationManager lm = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE); 
     if (!lm.isProviderEnabled(LocationManager.GPS_PROVIDER)) { 
      Toast.makeText(this, "Enable your GPS.",Toast.LENGTH_LONG).show(); 
      Intent intent = new Intent( 
       Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
       startActivity(intent); 
     } 

     Location loc = lm.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER); 
      Log.println(Log.ASSERT, "getLastKnownLocation()", loc.getLatitude() + " " + loc.getLongitude()); 
      lat = loc.getLatitude(); 
      lng = loc.getLongitude(); 
      latituteField.setText(lat + ""); 
      longitudeField.setText(lng + ""); 

      // THIS IS the standard 
      // Register the listener with the Location Manager to receive location updates 
      lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 500, 0, this); // Or NETWORK_PROVIDER 
     } 

      public void onLocationChanged(Location loc) { 
       lat = loc.getLatitude(); 
       lng = loc.getLongitude(); 
       DatabaseHandler db = new DatabaseHandler(this); 
       db.addCordinate(new Cordinates()); 
       handler.post(new Runnable() { 
         public void run() { 
          latituteField.setText(lat + ""); 
          longitudeField.setText(lng + "");        
         } 
       }); 
      } 

      @Override 
      public void onProviderDisabled(String provider) { 
       Toast.makeText(getApplicationContext(), "GPS Disabled " + provider,Toast.LENGTH_SHORT).show(); 
       Log.println(Log.ASSERT, "onProviderDisabled()", "Provider has been Disabled");    
      } 

      @Override 
      public void onProviderEnabled(String provider) { 
       // you could do things here, such as sense when a user has turned off the gps in setttings 
      } 

      @Override 
      public void onStatusChanged(String provider, int status, Bundle extras) { 
       // provides a lot of info that might be useful, such as the quality of the signal, etc. 
       Log.println(Log.ASSERT, "onStatusChanged()", "PROVIDER : " + provider 
         + " ~ " +"STATUS: " + status 
         + ". /// " + "EXTRAS? : " + extras 
         + "."); 

       Toast.makeText(getApplicationContext(), "Latitude: "+lat+ "\n"+" Longitude: "+lng, Toast.LENGTH_SHORT).show();    
      } 
     } 

任何人都可以跟踪我的代码，看看为什么我是渐渐空虚值每一行？另外为什么我有'TEXT'的列标签？

Answer 1

首先纠正你Create Table Query下面：

String CREATE_CORDINATES_TABLE = "CREATE TABLE " + TABLE_CORDINATES + "(" 
      + KEY_ID + " INTEGER PRIMARY KEY, " + KEY_LAT + " TEXT, " 
      KEY_LNG + " TEXT);"; 

Answer 2

你的领域KEY_LAT和KEY_LNG是整数，您尝试插入那里的浮点值。

您应该将值转换为整数，或将值和数据库字段都转换为TEXT。