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In what areas might the use of F# be more appropriate than C#? [closed]
...a structures used to represent program code in F# are mostly discriminated unions (which are not supported in C# in any reasonable way) and this makes a huge difference for this kind of application (where you need to process tree structures, such as program code). Discriminated unions and pattern ma...
MySQL Query - Records between Today and Last 30 Days
...
You can also write this in mysql -
SELECT DATE_FORMAT(create_date, '%m/%d/%Y')
FROM mytable
WHERE create_date < DATE_ADD(NOW(), INTERVAL -1 MONTH);
FIXED
share
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How do Python functions handle the types of the parameters that you pass in?
...tively.
Iterable - useful for generators.
Any - when it could be anything.
Union - when it could be anything within a specified set of types, as opposed to Any.
Optional - when it might be None. Shorthand for Union[T, None].
TypeVar - used with generics.
Callable - used primarily for functions, but ...
Laravel Eloquent ORM Transactions
...t ORM is quite nice, though I'm wondering if there is an easy way to setup MySQL transactions using innoDB in the same fashion as PDO, or if I would have to extend the ORM to make this possible?
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How do I insert NULL values using PDO?
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I had trouble with PDO::PARAM_NULL on MySql 5.1.53, but PDO::PARAM_INT with a null value worked great.
– Will Shaver
Dec 5 '11 at 19:33
2
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Best practices for SQL varchar column length [closed]
... table's varchar column. But I could not find any reference for that.
For MySQL the manual says "In most cases, ALTER TABLE makes a temporary copy of the original table". And my own tests confirm that: running an ALTER TABLE on a table with 1.2 million rows (the same as in my test with Postgres) to...
MQTT与TCP的区别 - 创客硬件开发 - 清泛IT社区，为创新赋能！
... Maori dictionary)。10. mqtt客户端connect时，可以带有用户名和密码，用于验证客户端。服务端可以根据clientid、IP地址、用户名等进行ACL访问控制。可以通过自定义应用消息实现客户端对服务端的身份验证。11. 有商业和开源的mqtt broke...
Linux C/C++程序常用的调试手段及异常排查总结 - C/C++ - 清泛网 - 专注C/C++及内核技术
...所有变量命名是否可以保持一致性？缩进，换行，可读性如何？
（驼峰、下划线，这个根据公司或者谷歌等的编码规范去做，至于缩进、换行、注释等，可以在经常使用的ide上安装相关格式化插件）
是否涉及动态资源
是...
SQL Group By with an Order By
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In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
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LIMIT 10..20 in SQL Server
... not part of standard SQL. It's supported as a vendor extension to SQL by MySQL, PostgreSQL, and SQLite.
Other brands of database may have similar features (e.g. TOP in Microsoft SQL Server), but these don't always work identically.
It's hard to use TOP in Microsoft SQL Server to mimic the LIMI...