如何使用Android中的SQLite数据库将两列相乘？

Question

我创建使用SQLiteOpenHelper表：

public void onCreate(SQLiteDatabase db) { 
     // TODO Auto-generated method stub 
     db.execSQL(
       "CREATE TABLE " + DATABASE_TABLE + " (" + 
       KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
       KEY_NAME + " TEXT NOT NULL, " + 
       KEY_SWIMMERLAPS + " INT NOT NULL, " + 
       KEY_SPONSOR + " DEC NOT NULL);" 

       ); 

我怎么会用一个SQLiteDatbase方法赞助商乘以游泳圈的价值观？

Answer 1

试试这个：

Cursor cursor = db.rawQuery("SELECT " + KEY_SWIMMERLAPS + " * " + KEY_SPONSOR + " AS result FROM " + DATABASE_TABLE, null); 

if (cursor.moveToFirst()){ 
    Log.w("result", cursor.getDouble(0)+""); 
}