大约有 7,000 项符合查询结果（耗时：0.0250秒） [XML]
SQL: How to perform string does not equal
... Just noticed that the <=> operator only exists in the MySQL world, for more info see what is <=>
– Top-Master
Apr 27 '19 at 6:18
...
Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法 - 数据库(内核) - 清...
...from tablexxx order by xxx desc ) where rownum <= Noracle数据库不支持mysql中limit, top功...select * from ( select * from tablexxx order by xxx desc ) where rownum <= N
oracle数据库不支持mysql中limit, top功能,但可以通过rownum来限制返回的结果集的行数,rownum并不...
Postfix日常维护队列管理 - 更多技术 - 清泛网 - 专注C/C++及内核技术
.../local/httpd/logs/error_log tail -f /usr/local/httpd/logs/suexec_log
mysql相关：tail -f /usr/local/mysql/data/linux.linux.com.err
测试amavisd：amavisd -d config debug-sa
测试spam：spamassassin -D --lint
测试maildrop：maildrop -V 10 -dtest@test.com
Postfix 维护 队列
PHP的函数前加上“@”的作用 - PHP - 清泛IT论坛，有思想、有深度
@是PHP提供的错误信息屏蔽的专用符号。
比如在一个函数前使用@
@mysql_query 不会出现Warning，
而原来mysql_query 在遇到错误时会在页面上访提示Warning。
What is the difference between an ORM and an ODM?
...(Object Document Mapper) deals with documents. Am I right in assuming that mySQL is an example of ORM and MongoDB is a example of ODM?
...
Simplest way to profile a PHP script
... all the data
$select_query = "SELECT * FROM data_table";
$result = mysql_query($select_query);
prof_flag("Retrieve data");
$rows = array();
$found_data=false;
while($r = mysql_fetch_assoc($result))
{
$found_data=true;
$rows[] = $r;
}
prof_flag("Close DB");
...
How can I implement a tree in Python?
... self.right = None
self.data = None
You can use it like this:
root = Tree()
root.data = "root"
root.left = Tree()
root.left.data = "left"
root.right = Tree()
root.right.data = "right"
If you need an arbitrary number of children per node, then use a list of children:
class Tree:
def...
Rails Root directory path?
How do I get my Rails app's root directory path?
9 Answers
9
...
Socket send函数和recv函数详解以及利用select()函数来进行指定时间的阻塞 ...
...有情况下，发送开始调用是局部的：无论其它进程的状态如何，它立刻返回。如果这个调用使得一些系统资源用完，那么它将失败并返回 一个错误代码。高质量的MPI实现应保证这种情况只在“病态”时发生。即，一个MPI实现将...
How long is the SHA256 hash?
...+ salt, but I don't know how long to make my VARCHAR when setting up the MySQL database. What is a good length?
5 Answers...