java - Android Studio sqlite 更新

Question

我制作了一个 sqlite 表，可以在其中为我的 Trip 应用程序插入数据。我正在尝试更新行，但我无法弄清楚。我已经搜索了很多，但我在更新部分做错了，我不知道是什么。

public static final String DATABASE_NAME = "triptracker.db";
public static final String TABLE_NAME = "trip_table";
public static final String COL_1 = "trip_id";
public static final String COL_2 = "trip_title";
public static final String COL_3 = "trip_description";
public static final String COL_4 = "trip_image";
public static final String COL_5 = "trip_location";

当我插入数据时：

public boolean insertData(String title, String description, String location) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2, title);
        contentValues.put(COL_3, description);
        // contentValues.put(COL_4, image);
        contentValues.put(COL_5, location);
        long result = db.insert(TABLE_NAME, null, contentValues);
        if (result == -1)
            return false;
        else
            return true;

    }


//When I'm updating the database

public boolean update(String title, String description, String location){
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2, title);
        contentValues.put(COL_3, description);
        contentValues.put(COL_5, location);
        db.update(TABLE_NAME,contentValues, "location=?", new String[]{location} );
        return true;

    }

// I need to press a button in order to save the data
        saveItem.setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {

              if(!editLocation.getText().toString().equals("") && !editTitle.getText().toString().equals("") && !editDescription.getText().toString().equals("")){
                    boolean insert = myDb.update(editLocation.getText().toString(),
                            editDescription.getText().toString(),
                            editTitle.getText().toString());
                }
                else {
                    Toast.makeText(singlemomentactivity.this, "Your moment is not added ", Toast.LENGTH_LONG);
                }

标签： javaandroidsqliteandroid-sqlite

Answer 1

试试这个，也许关键参考是问题所在。但是在你尝试这个之后让我知道。

public static final String DATABASE_NAME = "triptracker.db";
 public static final String TABLE_NAME = "trip_table";
public static final String COL_1 = "trip_id";
public static final String COL_2 = "trip_title";
public static final String COL_3 = "trip_description";
public static final String COL_4 = "trip_image";
public static final String COL_5 = "trip_location";
public static final String COL_6 = "ID";


//oncreate method of SQLite DB

@Override
public void onCreate(SQLiteDatabase db) {

    //Create Search Table

    String EXAMPLE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + "("
            + COL_6 + " INTEGER PRIMARY KEY AUTOINCREMENT,"
            + COL_1 + " TEXT UNIQUE,"
            + COL_2 + " TEXT,"
            + COL_3 + " TEXT,"
            + COL_4 + " TEXT,"
            + COL_5 + " TEXT,"
            + ")";

    db.execSQL(EXAMPLE_TABLE);
  }


public boolean update(String title, String description, String location){
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COL_2, title);
    contentValues.put(COL_3, description);
    contentValues.put(COL_5, location);

     //code for only if location is updated
     if(//location needs to be updated){

      ContentValues values = new ContentValues();
            values.put(COL_5,location);
            db.update(SarathCityLocalDatabase.EXAMPLE_TABLE,values,COL_6 + " = ?",new String[]{location});
     }
    return true;

}