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How to execute a raw update sql with dynamic binding in rails
...d try accessing the underlying connection and using it's methods, e.g. for MySQL:
st = ActiveRecord::Base.connection.raw_connection.prepare("update table set f1=? where f2=? and f3=?")
st.execute(f1, f2, f3)
st.close
I'm not sure if there are other ramifications to doing this (connections left op...
Why does “_” (underscore) match “-” (hyphen)?
...cluding zero characters).
(From section 3.3.4.7. Pattern Matching in the MySQL documentation.)
If you want to use the underscore in like as a literal, you have to escape it:
select * from a where name like '%taz\_manual%.pdf%';
...
Java 理论与实践: 线程池与工作队列 - 更多技术 - 清泛网 - 专注C/C++及内核技术
... POP)、通过 JMS 队列或者可能通过轮询数据库。不管请求如何到达,服务器应用程序中经常出现的情况是:单个任务处理的时间很短而请求的数目却是巨大的。
构建服务器应用程序的一个过于简单的模型应该是:每当一个请求...
UCenter实现各系统通信的原理 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...统通信的原理===本文导读===UCenter实现各系统通信的原理如何实现phpcms和discuz的Cookie同步===全文阅读===整合phpcms v9和discuz X3.2实现同步登陆、退出免激活===本文导读===
整合phpcms v9和discuz X3.2实现同步登陆、退出免激活
如何实现php...
String isNullOrEmpty in Java? [duplicate]
...that when I tried to use StringUtils my IDE (Eclipse) imported it from com.mysql.jdbc.StringUtils which actually has an isNullOrEmpty(myStringObject) method.
ex.
import com.mysql.jdbc.StringUtils;
StringUtils.isNullOrEmpty(host)
Just another alternative for those who already have the MySQL conne...
SQL - Select first 10 rows only?
...
select top 100 * from myTable
select top 100 colA, colB from myTable
In MySQL, use:
select ... order by num desc limit 10
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千亿时代 网游走到十字路口 - 资讯 - 清泛网 - 专注C/C++及内核技术
...能再缓的端游还能挺多久?手游作为游戏增长最大驱动力如何面临资本降温和淘汰加速的考验?电视游戏(包括主机游戏等)能不能接过力促增长的枪?虚拟现实是噱头还是真正的行业未来?这是个十字路口。
结构性调整
China...
Node.js vs .Net performance
...ization
nodejs: 228,887
aspnet-stripped: 105,272
Single Query
nodejs-mysql: 88,597
aspnet-stripped-raw: 47,066
Multiple Queries
nodejs-mysql: 8,878
aspnet-stripped-raw: 3,915
Plain Text
nodejs: 289,578
aspnet-stripped: 109,136
In all cases, Node.js tends to be 2x+ faster than IIS.
...
Is there any performance gain in indexing a boolean field?
...e an index, if you have too many records it doesn't use the index anyways.
MySQL not using index when checking = 1 , but using it with = 0
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What is SQL injection? [duplicate]
...d queries, or applying your language/toolkit's escaping functions (such as mysql_real_escape_string() in PHP).
Once you understand SQL Injection you'll get the joke behind this cartoon.
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