w 字段类型设置错误 有限元的判断,勿用枚举行. MySQL :: MySQL 5.7 Reference Manual :: 12.4.4 The ENUM Typehttps://dev.mysql.com/doc/refman/5.7/en/enum.html We strongly recommend that you do not use numbers as enumeration values, because it does not save on storage over th…

Topics Logical Values struct Bool A value type whose instances are either true or false. Numeric Values struct Int A signed integer value type. struct Double A double-precision, floating-point value type. struct Float A single-precision, floating-poi…

Enumeration应该算是程序语言里面比较通用的一个类型,在scala中也存在这样的类型, 我们看下Enumeration的定义: abstract class Enumeration (initial: Int) extends Serializable Enumeration是一个抽象类,它定义四个value方法,来设置内部的值, 四个value方法如下定义: /** Creates a fresh value, part of this enumeration. */ protecte…

一.C#中MessageBox.Show用法 MessageBox.Show (String) 显示具有指定文本的消息框. 由 .NET Compact Framework 支持. MessageBox.Show (IWin32Window, String) 在指定对象的前面显示具有指定文本的消息框. MessageBox.Show (String, String) 显示具有指定文本和标题的消息框.由 .NET Compact Framework 支持. MessageBox.Show (IWi…

https://msdn.microsoft.com/en-us/library/ms157328(v=SQL.100).aspx Expressions are used frequently in reports to control content and report appearance. Expressions are written in Microsoft Visual Basic, and can use built-in functions, custom code, glo…

DataGridView控件 DataGridView是用于Windows Froms 2.0的新网格控件.它可以取代先前版本中DataGrid控件,它易于使用并高度可定制,支持很多我们的用户需要的特性. 关于本文档: 本文档不准备面面俱到地介绍DataGridView,而是着眼于深入地介绍一些技术点的高级特性. 本文档按逻辑分为5个章节,首先是结构和特性的概览,其次是内置的列/单元格类型的介绍,再次是数据操作相关的内容,然后是主要特性的综述,最后是最佳实践. 大部分章节含有一个“Q & A”部…

QML Object Attributes Every QML object type has a defined set of attributes. Each instance of an object type is created with the set of attributes that have been defined for that object type. There are several different kinds of attributes which can…

What's In This Chapter? Features of ASP.NET MVC 6 Routing Creating Controllers Creating Views Validating User Inputs Using Filters Working with HTML and Tag Helpers Creating Data-Driven Web Applications Implementing Authentication and Authorization W…

https://github.com/PacktPublishing/Game-Development-Patterns-and-Best-Practices https://github.com/mattCasanova/Mach5 1. Introduction to Design Patterns (已看) 2. One Instance to Rule Them All - Singletons (已看) 3. Creating Flexibility with the Componen…

枚举部分 Enumeration part 使用枚举我们可以定义一些有名字的数字常量. 枚举通过 enum关键字来定义. Using enumerations, we can define some numeric constants with names. Enumeration is defined by the enum keyword. enum Direction { Up = 1, Down, Left, Right } 枚举是在运行时真正存在的一个对象,其中一个原因是因为这样可以从…