显示mysqli查询的单列值 [英] Display single column value of mysqli query

问题描述

如何从mysqli中获取单个列值?结果应该是只有一行的单行.

How can I get a single column value from mysqli? The result should be single row with only one column.

这是我尝试过的:

$query = "SELECT MAX(`userid`) FROM `user`";
$rlt = mysqli_query($this->db, $query);
echo $rlt['userid'];

推荐答案

执行查询后，您不会获取该行:

You are not fetching the row after executing the query:

$query = "SELECT MAX(`userid`) FROM `user'";
$rlt = mysqli_query($this->db,$query);
$row = mysqli_fetch_row($this->db, $rlt);
echo $row[0];

另一种选择是对计算字段使用别名并使用fetch_assoc:

The alternative would be to use an alias for the computed field and use fetch_assoc:

$query = "SELECT MAX(`userid`) as `maxid` FROM `user'";
$rlt = mysqli_query($this->db,$query);
$row = mysqli_fetch_assoc($this->db, $rlt);
echo $row['maxid'];

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