我的SQL查询有改进吗？

Question

is there any way to remove the MAX with something else, maybe the ASC LIMIT 1 to decrease database throttling? My query gets the maximum id and adds 1 to it.

This is my query:

$query = 'SELECT MAX(ID) +1 as maxidpost  
          FROM wp_posts';
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)) {
  echo 'p='. $row['maxidpost'];
}
mysql_close();

Answer 1

What does the database tell you about your query? If id is indexed then

mysql> explain select max(id) + 1 from times;
+----+-------------+-------+------+---------------+------+---------+------+------+------------------------------+
| id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra                        |
+----+-------------+-------+------+---------------+------+---------+------+------+------------------------------+
|  1 | SIMPLE      | NULL  | NULL | NULL          | NULL | NULL    | NULL | NULL | Select tables optimized away |
+----+-------------+-------+------+---------------+------+---------+------+------+------------------------------+
1 row in set (0.18 sec)

mysql> explain select id from times order by id ASC limit 1;
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
| id | select_type | table | type  | possible_keys | key     | key_len | ref  | rows | Extra       |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
|  1 | SIMPLE      | times | index | NULL          | PRIMARY | 4       | NULL |    1 | Using index |
+----+-------------+-------+-------+---------------+---------+---------+------+------+-------------+
1 row in set (0.00 sec)