大约有 40,000 项符合查询结果（耗时：0.0101秒） [XML]
Database development mistakes made by application developers [closed]
... the log output from Hibernate and you'll see all the queries begin with:
SELECT DISTINCT ...
This is a bit of a shortcut to ensuring you don't return duplicate rows and thus get duplicate objects. You'll sometimes see people doing this as well. If you see it too much it's a real red flag. Not...
MySQL LIKE IN()?
... might be more efficient, but you'd have to benchmark it to be sure, e.g.
SELECT * from fiberbox where field REGEXP '1740|1938|1940';
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...
generate days from date range
...000 days, and could be extended to go as far back or forward as you wish.
select a.Date
from (
select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a) + (1000 * d.a) ) DAY as Date
from (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all ...
What is the difference between JOIN and UNION?
...t -- completely different operations. Trivial example of UNION:
mysql> SELECT 23 AS bah
-> UNION
-> SELECT 45 AS bah;
+-----+
| bah |
+-----+
| 23 |
| 45 |
+-----+
2 rows in set (0.00 sec)
similary trivial example of JOIN:
mysql> SELECT * FROM
-> (SELECT 23 AS bah...
CruiseControl.Net 进行持续化集成 - IT产品资讯 - 清泛网 - 专注C/C++及内核技术
...处 ，欢迎访问http://jillzhang.cnblogs.com/来获取最新更新
如何安装CC.Net
CC.Net是一款开源软件，它的官方主页是： http://confluence.public.thoughtworks.org/display/CCNET/Welcome+to+CruiseControl.NET
打开它的主页，便能看出他的官方采用另外一...
FIND_IN_SET() vs IN()
...
SELECT name
FROM orders,company
WHERE orderID = 1
AND companyID IN (attachedCompanyIDs)
attachedCompanyIDs is a scalar value which is cast into INT (type of companyID).
The cast only returns numbers up to the...
SQL MAX of multiple columns?
...
Well, you can use the CASE statement:
SELECT
CASE
WHEN Date1 >= Date2 AND Date1 >= Date3 THEN Date1
WHEN Date2 >= Date1 AND Date2 >= Date3 THEN Date2
WHEN Date3 >= Date1 AND Date3 >= Date2 THEN Date3
ELSE ...
整合phpcms v9和discuz X3.2实现同步登陆、退出免激活 - 更多技术 - 清泛网...
...案，那就是通过UCenter实现多系统间通信，这里主要介绍如何配置实现同步登陆、退出。===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...
【App Inventor 2 数据可视化】使用柱状图和饼图收集数据 - App应用开发 - ...
...图和饼图收集数据跟踪我的情绪这个渐进式的指南告诉你如何创建一个App来跟踪你一周或一个月的情绪，并可视化数据。基于我们流行的Mood Ring教程，这款应用更进一步——它允许你创建一个可视化的Happy、Angry和Sad的天数。完...
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...相互不认识，明明想给丽丽写一封情书，让隔壁老王送去如何保证隔壁老王不能看到情书内容？（保密性)如何保证隔壁老王不修...
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如何保证隔壁...