如何在Android中使用SQLite数据库将两列相乘？

Question

我使用SQLiteOpenHelper创建了一个表：

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 );"

                );

我如何使用SQLiteDatbase方法将赞助商的游泳圈数值乘以？

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)+"");
}