总和：两个不同的时间查询

Question

I set up my MySQL database with the field 'buy_datetime' and sell_datetime . I want to get result of total time with different datetime in Hours. Format: '1000-01-01 00:00:00' .

For example,

1. buy_datetime - sell_datetime = 1result
2. buy_datetime - sell_datetime = 2result

OUTPUT Total in hours = 1resul + 2result .

    public function firstHourHoldingTime(){

        $count_firsthour_holding_time =  DB::table('finaltrade')
            ->select(DB::raw('finaltrade.*'))
            ->sum(TIMEDIFF(Hour,"buy_datetime", "sell_datetime"))
            ->get();
    }

Answer 1

You need raw expression to sum up hourly difference between your columns

public function firstHourHoldingTime(){

    $count_firsthour_holding_time =  DB::table('finaltrade')
        ->select(DB::raw('SUM(TIMESTAMPDIFF(HOUR,buy_datetime, sell_datetime)) as total'))
        ->get();
}