大约有 7,000 项符合查询结果（耗时：0.0281秒） [XML]
Favourite performance tuning tricks [closed]
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Assuming MySQL here, use EXPLAIN to find out what is going on with the query, make sure that the indexes are being used as efficiently as possible and try to eliminate file sorts. High Performance MySQL: Optimization, Backups, Replica...
How to change the name of a Django app?
...E <oldAppName>_modelName RENAME TO <newAppName>_modelName. For mysql too I think it is the same (as mentioned by @null_radix)
(For Django >= 1.7) Update the django_migrations table to avoid having your previous migrations re-run: UPDATE django_migrations SET app='<NewAppName>' W...
Deep Learning（深度学习）学习笔记整理系列之（二） - 大数据 & AI - 清泛...
...，不妨把这个碎片标记为 T。
他们提出的问题是，如何从这400个碎片中，选取一组碎片，S[k], 通过叠加的办法，合成出一个新的碎片，而这个新的碎片，应当与随机选择的目标碎片 T，尽可能相似，同时，S[k] 的数量尽可...
How to get last inserted row ID from WordPress database?
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Putting the call to mysql_insert_id() inside a transaction, should do it:
mysql_query('BEGIN');
// Whatever code that does the insert here.
$id = mysql_insert_id();
mysql_query('COMMIT');
// Stuff with $id.
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Android中Java和JavaScript交互 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...页中，JavaScript又是一个很举足轻重的脚本。本文将介绍如何实现Java代码和Javascript代码的相互调用。如何实现
实现Java和js交互十分便捷。通常只需要以下几步：
WebView开启JavaScript脚本执行。
WebView设置供JavaScript调用的交互接...
【软著】软件著作权证书申请流程及注意事项，模板分享 - App Inventor 2 中...
...码文档中不要有代码空行及注释。50行*60页
6、AppInventor2如何申请软著？
一般的软件比如使用Java开发，源码中准备的就是.java代码，但是appinventor没有具体的代码怎么办？不要紧，将.aia导出后，用压缩软件打开aia源码，在src目...
Check if table exists without using “select from”
...elf stated to do it is the proper way. There is no 'exists' type statement MySql. 'Exists' in MySql is a clause which requires an operation such as SELECT, UPDATE, or DELETE.
– doogle
Jan 12 '12 at 1:51
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2016年最适合小投资的10个创业项目 - 资讯 - 清泛网 - 专注C/C++及内核技术
...，面对行行色色的创业项目让很多人挑花了眼，不知道该如何抉择。创业看似很难其实简单，抓住好项目你就勇敢之前！小投资创业项目是很多创业者的首选，面对行行色色的创业项目让很多人挑花了眼，不知道该如何抉择。小...
Referring to a Column Alias in a WHERE Clause
... I think using HAVING on aliases is not standard (it does works on MySQL, though). Specifically, I think it does not work with SQL Server.
– tokland
Nov 25 '16 at 12:10
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Explicit vs implicit SQL joins
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On MySQL 5.1.51, both queries have identical execution plans:
mysql> explain select * from table1 a inner join table2 b on a.pid = b.pid;
+----+-------------+-------+------+---------------+------+---------+--------------+---...