大约有 18,336 项符合查询结果（耗时：0.0638秒） [XML]
When to use .First and when to use .FirstOrDefault with LINQ?
... @driis - I'd imagine we can use the mantra of the exceptional exception guideline when choosing between First and FirstOrDefault. Thanks for the clear answer.
– Metro Smurf
Jun 21 '09 at 21:21
...
How do you do a limit query in JPQL or HQL?
...tMaxResults().
So if it worked in Hibernate 2, it seems that was by coincidence, rather than by design. I think this was because the Hibernate 2 HQL parser would replace the bits of the query that it recognised as HQL, and leave the rest as it was, so you could sneak in some native SQL. Hibernate ...
How to declare a variable in a PostgreSQL query
...
This is ideal for when I have a migration script where I want to import some relational data. Obviously I won't know the sequence id the relational data is given.
– Relequestual
Feb 13 '15 at 9:...
Check if checkbox is checked with jQuery
How can I check if a checkbox in a checkbox array is checked using the id of the checkbox array?
23 Answers
...
Jenkins Host key verification failed
...tal: The remote end hung up unexpectedly
– A. M. Mérida
Mar 4 '13 at 8:40
6
...
mongodb count num of distinct values per field/key
...
},
{ $unwind: "$keywords" },
{
$group: {
_id: {$toLower: '$keywords'},
count: { $sum: 1 }
}
},
{
$match: {
count: { $gte: 2 }
}
},
{ $sort : { count : -1} },
{ $limit : 100 }
]);
that give result s...
廉价共享存储解决方案2-drbd+cman+gfs2 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...lic/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
a9:8a:3a:3d:64:eb:0b:de:94:a5:92:e4:ba:5d:f3:de root@gfs_1
The key's rand...
What is the difference between a stored procedure and a view?
...nd why to use each.
Say I have two tables:
tbl_user, with columns: user_id, user_name, user_pw
tbl_profile, with columns: profile_id, user_id, profile_description
So, if I find myself querying from those tables A LOT... instead of doing the join in EVERY piece of SQL, I would define a view like...
搭建高可用mongodb集群（二）—— 副本集 - 大数据 & AI - 清泛网 - 专注C/...
...admin数据库
use admin
#定义副本集配置变量，这里的 _id:”repset” 和上面命令参数“ –replSet repset” 要保持一样。
config = { _id:"repset", members:[
{_id:0,host:"192.168.1.136:27017"},
{_id:1,host:"192.168.1.137:27017"},
{_id:2,host:...
Why can't Python parse this JSON data?
...
Your data is not valid JSON format. You have [] when you should have {}:
[] are for JSON arrays, which are called list in Python
{} are for JSON objects, which are called dict in Python
Here's how your JSON file should look:
{
"maps": [...