大约有 40,000 项符合查询结果（耗时：0.0240秒） [XML]
What is in your Mathematica tool bag? [closed]
...pplication of Reap and Sow which mimics/extends the behavior of GatherBy:
SelectEquivalents[x_List,f_:Identity, g_:Identity, h_:(#2&)]:=
Reap[Sow[g[#],{f[#]}]&/@x, _, h][[2]];
This allows me to group lists by any criteria and transform them in the process. The way it works is that a c...
Windows下MySql安装配置 - 更多技术 - 清泛网 - 专注C/C++及内核技术
Windows下MySql安装配置1.下载服务器端，解压2.安装Mysql服务：进入bin目录，mysqld.exe --install (指定安装的MySql服务名)。（卸载 net stop servicename;...1.下载服务器端，解压
2.安装Mysql服务：
进入bin目录，mysqld.exe --install (指定安装的MyS...
JAVA敏捷开发环境搭建 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...前面介绍了创业型软件公司的工作模式，这里详细介绍下如何实施，第一步是先要搭建环境，有了环境才能开展工作。整个软件项目分为四个环境 ...前面介绍了创业型软件公司的工作模式，这里详细介绍下如何实施，第一步是...
笨法玩电商网站秒杀 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...锁检测虽然可以提升一定的性能，但这顶多是治标而已，如何治本？淘宝给出来两个改进方法：
请求排队：如果请求一股脑的涌入数据库，势必会由于争抢资源造成性能下降，通过排队，让请求从混沌到有序，从而避免数据...
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (111)
...this error(if there is no replication enabled):
run the command vim /etc/mysql/my.cnf
comment bind-address = 127.0.0.1 using the # symbol
restart your mysql server once.
Update
In Step 1, if you cannot find bind-address in the my.cnf file, look for it in /etc/mysql/mysql.conf.d/mysqld.cnf file....
LINQ to SQL - Left Outer Join with multiple join conditions
...g.Where(f => f.otherid == 17).DefaultIfEmpty()
where p.companyid == 100
select f.value
Or you could use a subquery:
from p in context.Periods
join f in context.Facts on p.id equals f.periodid into fg
from fgi in (from f in fg
where f.otherid == 17
select f).DefaultIfE...
Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
I have installed MySQL server and trying to connect to it, but getting the error:
18 Answers
...
Check for changes to an SQL Server table?
...
Take a look at the CHECKSUM command:
SELECT CHECKSUM_AGG(BINARY_CHECKSUM(*)) FROM sample_table WITH (NOLOCK);
That will return the same number each time it's run as long as the table contents haven't changed. See my post on this for more information:
CHECKSUM...
How do I check if there are duplicates in a flat list?
...6]), set([2, 3]))
"""
return reduce(
lambda (u, d), o : (u.union([o]), d.union(u.intersection([o]))),
a_list,
(set(), set()))
if __name__ == "__main__":
import doctest
doctest.testmod()
From there you can test unicity by checking whether the second element ...
App Inventor 2 低功耗蓝牙(BLE) 硬件接入、数据通信及IO控制 · App Inventor 2 中文网
...本文主要介绍一款较为通用、价格低廉的BLE设备从零开始如何利用App Inventor 2开发一款自己专属的手机蓝牙App应用。
BLE与经典蓝牙的区别可参考：《低功耗蓝牙(BLE) 和 经典蓝牙(SPP) 的区别》。
本文主要通过一款常见的BLE硬件...