Question

我有一个名为Live的表格，在表格中我有public_id。在public_id中是数字（例如1,2,3,4,5）。如何获得最高编号或最后一个条目的编号？

Answer 1

我会选择

SELECT public_id FROM Live ORDER BY public_id DESC LIMIT 1;

它已经发布，但我会添加更多内容：

如果通常执行此查询，则可以创建具有反向排序的索引。

类似的东西：

CREATE INDEX ON Live (public_id DESC)

请注意

DESC

PHP + MySQL代码：

<?php
$result = mysql_query('SELECT public_id FROM Live ORDER BY public_id DESC LIMIT 1;');
if (mysql_num_rows($result) > 0) {
   $max_public_id = mysql_fetch_row($result);
   echo $max_public_id[0]; //Here it is
}
?>

Answer 2

SELECT public_id FROM Live ORDER BY public_id DESC LIMIT 1;

会给你最高的数字

编辑：对于php

$conn = mysql_connect(....
$query = "SELECT public_id FROM Live ORDER BY public_id DESC LIMIT 1";
$result = mysql_query($query, $conn);

Answer 3

另一种选择是使用MAX，即

SELECT MAX(public_id) FROM Live

Answer 4

你可以使用ORDER BY public_id DESC LIMIT 1;获取id最高的记录（我猜你在public_id上使用autoincrement属性）或MySQL MAX()这样的函数：

SELECT * FROM table WHERE public_id = MAX(public_id);

编辑：

以下是如何在php中执行此操作：

// executing the QUERY request to MySQL server, mysql_query() returns resource ID
$result = mysql_query('SELECT public_id FROM Live ORDER BY public_id DESC LIMIT 1');
// then we use this resource ID to fetch the actual value MySQL have returned
$row = mysql_fetch_array($result, MYSQL_FETCH_ASSOC);
// $row variable now holds all the data we got from MySQL, its an array, so we just output the public_id column value to the screen
echo $row['public_id']; // you can use var_dump($row); to see the whole content of $row

如何获取MySQL的最后一行值？

4 个答案: