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How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?
...DROP { [ CONSTRAINT ] constraint_name | COLUMN column } [ ,...n ]
For MySQL:
ALTER TABLE TableName
DROP COLUMN Column1,
DROP COLUMN Column2;
or like this1:
ALTER TABLE TableName
DROP Column1,
DROP Column2;
1 The word COLUMN is optional and can be omitted, except for RENAME...
log messages appearing twice with Python Logging
...g is left set to True. A
common scenario is to attach handlers only to the root logger, and to
let propagation take care of the rest.
So, if you want a custom handler on "test", and you don't want its messages also going to the root handler, the answer is simple: turn off its propagate flag:
logger...
MySQL select where column is not empty
In MySQL, can I select columns only where something exists?
13 Answers
13
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SQL Server equivalent of MySQL's NOW()?
I'm a MySQL guy working on a SQL Server project, trying to get a datetime field to show the current time. In MySQL I'd use NOW() but it isn't accepting that.
...
'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error
...can use this JDBC URL directly in your data source configuration:
jdbc:mysql://yourserver:3306/yourdatabase?zeroDateTimeBehavior=convertToNull
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内存管理内幕：动态分配的选择、折衷和实现 - C/C++ - 清泛网 - 专注C/C++及内核技术
...点是 C 语言，但同样也适用于其他语言。文中将为您提供如何管理内存的细节，然后将进一步展示如何手工管理内存，如何使用引用计数或者内存池来半手工地管理内存， 以及如何使用垃圾收集自动管理内存。为什么必须管理...
Change limit for “Mysql Row size too large”
... You may want to take a look at this article which explains a lot
about MySQL row sizes. It's important to note that even if you use
TEXT or BLOB fields, your row size could still be over 8K (limit for
InnoDB) because it stores the first 768 bytes for each field inline in
the page.
The...
For loop example in MySQL
In MySQL, I have this stored procedure with a For loop in it:
4 Answers
4
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那些曾被追捧的90后创业男神女神，还好吗？ - 资讯 - 清泛网 - 专注C/C++及内核技术
...右，距离1%还差不少。但不晓得安妮以及她的团队今后会如何去做，或许这样让人眼前一亮的作品再次出现要等很久，但我们却不得不承认，这次的1%亮了。
点评：鸡汤是这个时代最好的精神补品，但此前以漫画形式成功的案例...
从Sloodle看三维虚拟学习环境的发展趋势 - 资讯 - 清泛网 - 专注C/C++及内核技术
...游戏 ,吸引了越来越多的关注。现在的教育者也开始探索如何让学生在学习时也能像玩游戏一样沉浸其中。在游戏中需要解决一些交流、协作问题 ,这在学习系统中也会同样关注 ,因此很多学者也开始研究非正式学习领域内如何将...