PHP：如何获得变量列中的值的总和

Question

我试图从表中获得工资列的总和。我只需要回复总薪水。我试过了，

SELECT SUM(SalaryCol) FROM my_table;

我怎样才能得到查询结果作为PHP变量？

Answer 1

SELECT SUM(SalaryCol) as total_salary FROM my_table; 

Answer 2

$sql = 'SELECT SUM(SalaryCol) as total_salary FROM my_table'; 

//$con is your connection variable 
$result=mysqli_query($con,$sql); 

while($row=mysqli_fetch_array($result,MYSQLI_NUM)){ 
    $salaries[] = $row['total_salary']; 
} 
return $salaries; 

然后你可以访问此作为数组，做任何

Answer 3

好吧，我理解了它自己。

$query = "SELECT SUM(SalaryCol) FROM my_table";

$sum = mysqli_fetch_row(mysqli_query($con, $query));

echo "Total : ".$sum[0];