Question

这里我要PF计算，我们每个月扣除pf，现在我想显示总pf数量。这是我的数据库表结构

id    first_name   pf_amount   pf_month    badge_number

1      Kani         200         01-2017      01

2      Mahesh       250         01-2017      02

3      Kani         200         02-2017      01

4      Mahesh       250         02-2017      02

在我的列表页面中，我想显示有400的badge_number（01）和有500的badge_number（02）。这里，badge_number是唯一的

我这样写了查询，但是我在这里得到了所有数据，如何根据我的要求做了

$check = mysql_query("SELECT * FROM pf_history");
while($row = mysql_fetch_array($check)) {
   echo $row['pf_amount'];
}

Answer 1

在查询中使用GROUP BY和SUM（）：

SELECT first_name, pf_month, SUM(pf_amount) as total FROM pf_history GROUP BY badge_number

<强>代码：

$check = mysqli_query("SELECT first_name, pf_month, SUM(pf_amount) as total FROM pf_history GROUP BY badge_number");
while($row = mysqli_fetch_array($check)) {
  echo $row['total'];
}

group by和sum（）的

参考：

GROUP BY

SUM()

Answer 2

您应该使用sum()和group by，如下所示：

SELECT first_name, pf_month, badge_number, SUM(pf_amount) as total_pf_amount
FROM pf_history 
GROUP BY badge_number

PHP：

$check = mysql_query("SELECT first_name, pf_month, badge_number, SUM(pf_amount) as total_pf_amount
    FROM pf_history 
    GROUP BY badge_number");
while($row = mysql_fetch_array($check)) {
    echo $row['total_pf_amount'];
}

reference

如何进行粉煤计算以及如何显示总粉煤量

2 个答案: