從選擇查詢中的兩個不同表中減去兩個不同的列總和

Question

我有兩個表，名稱分別為add_sell和add_expense。 我已經在表中插入了一些價值。 我想獲得總利潤結果。 我自己做了，但結果顯示為0。 現在我該怎么做。 我還給出了總利潤公式。 有人在這里幫助我嗎？ 這是下面給出的代碼

function totalSell(){
    global $conn;
    $sql = "SELECT SUM(`sell_amount`) as 'Sumearning' FROM `add_sell` WHERE sell_amount = `sell_amount`";
        $result = $conn->query($sql);
        $getDate = date('d/m/Y');                    
        if(mysqli_num_rows($result) > 0){

        while($fetch = mysqli_fetch_array($result)){                  
        echo "SR ".$fetch['Sumearning']; 
       }
    }
}

function totalExpense(){
    global $conn;
    $ex = "SELECT SUM(`expense_amount`) as `Sumexpense` FROM `add_expense` WHERE expense_amount = `expense_amount` ";
    $run_ex = $conn->query($ex);
    if (mysqli_num_rows($run_ex) > 0) {
        while ($tex = mysqli_fetch_array($run_ex)) {
        echo "SR ".$tex['Sumexpense'];
        }
    }
}

函數totalProfit（）{

    global $conn;

    $sql = "SELECT SUM(`sell_amount`) as 'Sumearning' FROM `add_sell` WHERE sell_amount = `sell_amount`";
        $result = $conn->query($sql);
        $getDate = date('d/m/Y');
        while($fetch = mysqli_fetch_array($result)){                  
            $fetch['Sumearning']; 
            echo "Total Earning : ".$totalEarning = "SR ".$fetch['Sumearning']; 
       }

$ex = "SELECT SUM(`expense_amount`) as `Sumexpense` FROM `add_expense` WHERE expense_amount = `expense_amount` ";
        $run_ex = $conn->query($ex);

        while ($tex = mysqli_fetch_array($run_ex)) {
            $tex['Sumexpense'];
            echo "Total Expense : ".$totlaExpenss = "SR ".$tex['Sumexpense'];
        }
        echo "Your totla Profit is : ".$totalprofit = $totalEarning - $totlaExpenss;
}

Answer 1

您是說要獲得總收入和總支出之間的差額嗎？ 因為可以這樣嗎？

$ Total = $ tex ['Sumexpense']-$ fetch ['Sumearning'];

總回聲

Answer 2

您可以從查詢本身獲得總利潤結果。

$sql = "SELECT SUM(`sell_amount`)-(SELECT SUM(`expense_amount`) FROM `add_expense` WHERE expense_amount = `expense_amount`)  AS `PROFITLOSS` FROM `add_sell` WHERE sell_amount = `sell_amount`";

注意：作為Sumearning和Sumexpense Removed，您將得到PROFITLOSS