The book is filled with buggy programs. This allows you to learn from the misfortunes of others. It contains bugs that I've found, bugs found by my friends and other programmers. Each program is a learning experience. The programs presented here are
对查询进行优化,应尽量避免全表扫描,首先应考虑在 where 及 order by 涉及的列上建立索引。 2.应尽量避免在 where 子句中对字段进行 null 值判断,否则将导致引擎放弃使用索引而进行全表扫描,如: select id from t where num is null 可以在num上设置默认值0,确保表中num列没有null值,然后这样查询: select id from t where num=0
Keyboard shortcuts A quick reference guide to UltraEdit's default keyboard shortcuts Keymapping and custom hotkeys How to customize 键映射s and menu hotkeys Column Markers The benefit of a column maker is that it can help you to format your text/code,
iOS Core Animation: Advanced Techniques 中文译本 Core Animation is the technology underlying Apple’s iOS user interface. By unleashing the full power of Core Animation, you can enhance your app with impressive 2D and 3D visual effects and create excitin
These tips and comments are intended for user education purposes only. They are to be used at your own risk. The contents are based on my experience with ANSYS 5.3 -- more recent versions may change things. The contents do not attempt to discuss all
57. What is the requirement for phase noise at 1k offset, 10kHz offset, and 100kHz offset for GSM handset? GSM手机的相位噪声为1k、10kHz和100kHz的情况下,需要满足什么条件?答:For GSM handset RX it has several architectures to implement: Superheterodyne,near zero-IF,zero-IF,di
29. What is the requirement for phase noise at 1k offset, 10kHz offset, and 100kHz offset for GSM handset? GSM手机的相位噪声为1k、10kHz和100kHz的情况下,需要满足什么条件?答:For GSM handset RX it has several architectures to implement: Superheterodyne,near zero-IF,zero-IF,di
Composer是新一代的PHP依赖管理工具。其介绍和基本用法可以看这篇《PHP管理依赖(dependency)关系工具 Composer 安装与使用》。本文介绍使用Composer的五个小技巧,希望能给你的PHP开发带来方便。
1. 仅更新单个库
只想更新某个特定的库,不想更新它的所有依赖,很简单:
composer update foo/bar
此外,这个技巧还可以用来解决“警告信息问题”。你一定见过这样的警告信息:
Warning: The lock file is not up t