Question

我有一个如下所示的数据库：

Employee_id  dev_hours Pm_hours
1                2         2
1                3         3
2                3         3
3                2         1 
3                1         1

我如何使用php查找每个员工工作的总小时数？例如，员工1工作总共10小时，员工3工作总共5小时？

Answer 1

您需要使用SUM()和GROUP BY。尝试：

SELECT Employee_id, SUM(dev_hours + Pm_hours) as total_hours FROM tbl GROUP BY Employee_id

Answer 2

从W3学校获取的略有变化PHP指南：

http://www.w3schools.com/php/php_mysql_select.asp

<?php
$con = mysql_connect("server","user","password");
if (!$con)
{
  die('Could not connect: ' . mysql_error());
}

mysql_select_db("my_db", $con);

$result = mysql_query("SELECT Employee_id, SUM(dev_hours + Pm_hours) as Hours FROM EmployeeTable GROUP BY Employee_id");

while($row = mysql_fetch_array($result))
{
  echo $row['Employee_id'] . " " . $row['Hours'];
  echo "<br />";
}

mysql_close($con);
?>

计算字段的多个条目的总计

2 个答案: