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What are the use cases for selecting CHAR over VARCHAR in SQL?
...the same length (within two characters length difference).
Note: Microsoft SQL has 2 bytes of overhead for a VARCHAR. This may vary from DB to DB, but generally, there is at least 1 byte of overhead needed to indicate length or EOL on a VARCHAR.
As was pointed out by Gaven in the comments: Things ch...
Copying PostgreSQL database to another server
I'm looking to copy a production PostgreSQL database to a development server. What's the quickest, easiest way to go about doing this?
...
How to check if a stored procedure exists before creating it
I have a SQL script that has to be run every time a client executes the "database management" functionality. The script includes creating stored procedures on the client database. Some of these clients might already have the stored procedure upon running the script, and some may not. I need to have...
How to convert float to varchar in SQL Server
...number is
CONVERT (VARCHAR(50), float_field,128)
See http://www.connectsql.com/2011/04/normal-0-microsoftinternetexplorer4.html
The other solutions above will sometimes round or add digits at the end
UPDATE: As per comments below and what I can see in https://msdn.microsoft.com/en-us/library/m...
How Do I Get the Query Builder to Output Its Raw SQL Query as a String?
...
Use the toSql() method on a QueryBuilder instance.
DB::table('users')->toSql() would return:
select * from `users`
This is easier than wiring up an event listener, and also lets you check what the query will actually look lik...
What is an ORM, how does it work, and how should I use one? [closed]
...that encapsulates the code needed to manipulate the data, so you don't use SQL anymore; you interact directly with an object in the same language you're using.
For example, here is a completely imaginary case with a pseudo language:
You have a book class, you want to retrieve all the books of whic...
获得ActiveX控件所在网页的对象模型 - C/C++ - 清泛网 - 专注C/C++及内核技术
...档的对象模型，即document,element等
1. 获得IWebBrowserApp，使用
a.使用IOleClientSite接口获得IServiceProvider接口：
CComQIPtr pISP;
pClientSite->QueryInterface(IID_IServiceProvider, (void **)&pISP);
b.使用IServiceProvider接口获得IWebBrowserApp接口：
pISP->QueryS...
选中CListCtrl指定行并发送LVN_ITEMCHANGED消息 - C/C++ - 清泛网 - 专注C/C++及内核技术
选中CListCtrl指定行并发送LVN_ITEMCHANGED消息在使用CListCtrl列表控件的程序中，当我们修改了CListCtrl后需要要定位到已修改的行，可以使用下面的函数实现： 定位并使指定行选中m_list...在使用CListCtrl列表控件的程序中，当我们修改...
注册DLL时报错：模块已加载，但对DllRegisterServer的调用失败，错误代码为...
...的调用失败，错误代码为 0x80070005错误代码0x80070005是没有使用管理员权限进行注册。因此，使用管理员权限注册DLL即可解决，步骤如下：Win键，搜索cmd，右键以管理员身份运...
错误代码0x80070005是没有使用管理员权限进行注册...
MFC CSyncObject，CSingleLock，CMultiLock同步类 - C/C++ - 清泛网 - 专注C/C++及内核技术
... 1、纯虚类，作为具体同步类的基类，它只作为一个接口使用
2、有两个关键的成员函数Lock()、UnLock()，CSyncObject后面的四类都通过这两个统一接口进行同步操作。
1）不带参数的 UnLock() 是纯虚函数，在CSyncObject类中没有...