希望我能解决我遇到的 LEFT JOIN + SUM 问题。
背景:我正在构建一个小型财务系统,并希望计算给定月份(空白月份 = 空)内所有发票的值(value)。我有两个表:
tsm_finance_calendar - 包含“月份”。 tsm_finance_invoices - 包含每张发票的详细信息。
我的查询:
<?php
$query = "SELECT tsm_finance_calendar.month,
SUM(tsm_finance_invoices.totalBilled)
FROM tsm_finance_calendar
LEFT JOIN tsm_finance_invoices
ON tsm_finance_calendar.month = tsm_finance_invoices.month
GROUP BY tsm_finance_calendar.month
ORDER BY 'id'";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
echo $row['month']. " - $". $row['SUM(totalBilled'];
echo "<br />";
}
?>
输出在正确的轨道上(月份 - $空白)但缺少求和结果。
任何帮助都会得到巨大的击掌:)
谢谢, RR
最佳答案
在查询中使用as
关键字
$query = "SELECT tsm_finance_calendar.month, SUM(tsm_finance_invoices.totalBilled) as sum FROM tsm_finance_calendar LEFT JOIN tsm_finance_invoices ON tsm_finance_calendar.month = tsm_finance_invoices.month GROUP BY tsm_finance_calendar.month ORDER BY 'id'";
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
echo $row['month']. " - $". $row['sum'];
echo "<br />";
}
关于php - LEFT JOIN 与 SUM 不工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4644241/