使用MySQLi求和的单个结果 [英] Single Result From SUM With MySQLi

问题描述

环顾四周.找不到答案. PHP文档尚不清楚(对我来说).

Looked all over. Can't find an answer. PHP docs not clear (to me).

我正在通过mysqli->query做一个简单的MySQL求和.我如何像mysql_result一样使用MySQLi获得结果?

I'm doing a simple MySQL sum through mysqli->query. How can I get the result with MySQLi like mysql_result?

推荐答案

(提意见以回答)

如果查询成功，则SELECT语句中给mysqli_query的任何内容都将返回mysql_result类型.因此，如果您有SELECT语句，例如:

Whatever is given in the SELECT statement to mysqli_query is going to return a mysql_result type if the query was successful. So if you have a SELECT statement such as:

SELECT sum(field) FROM table1

您仍然需要使用结果获取行，sum()函数的值将是行数组中的唯一条目:

you still need to fetch the row with the result, and the value of the sum() function will be the only entry in the row array:

$res = mysqli_query($dbh,'SELECT sum(field) FROM table1');
if (FALSE === $res) die("Select sum failed: ".mysqli_error);
$row = mysqli_fetch_row($res);
$sum = $row[0];

*请记住检查mysqli_query的返回值，以确保查询不会失败.*

*Remember to check the return from mysqli_query to ensure the query did not fail.*

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