列中的最大值 - Maximum value in a column

Maximum value in a column

本文关键字：最大值 | 更新日期: 2023-09-27

有没有更有效的方法呢？我想要使用 PHP 的给定 MySQL 表中列（int）的最大值。

$results = $conn->query("SELECT statement_id FROM statement ORDER BY statement_id DESC LIMIT 1");
$next_statment_id = $results->fetch_assoc();
$next_statment_id = $next_statment_id['statement_id'];
echo $next_statment_id;

MAX

也是一个OK的方法

SELECT MAX(statement_id) AS statementIdentity 
  FROM statement;

输出产生如下内容：-

+-------------------+
| statementIdentity |
+-------------------+
|       4           |
+-------------------+

请考虑以下事项：

SELECT COUNT(*) FROM test;
+----------+
| COUNT(*) |
+----------+
| 10000000 |
+----------+
SELECT i FROM test ORDER BY i DESC LIMIT 1;
+----------+
| i        |
+----------+
| 18482903 |
+----------+
1 row in set (0.00 sec)
SELECT MAX(i) FROM test;
+----------+
| MAX(i)   |
+----------+
| 18482903 |
+----------+
1 row in set (0.00 sec)

看。里面不多。