小编Car*_*ter的帖子

我目前正在重构一些旧代码.我正在寻找有关最佳设计模式的说明.我在考虑工厂模式,但我不确定这是不是最好的方式.

所以这里是伪代码的简要概述.Foo类具有核心业务逻辑.

Class Foo{
    private List<Things> stuff;
    private static Integer count; 
    //getter setter for stuff

    public Foo(List<Things> stuff){
        this.stuff = stuff; 
        this.count=1;
    }

    //the following 3 methods are 90% similar

    public List<Newthings> doSomeThingFirst(){
        //uses the list stuff and also increments the static member count for each entry in List<NewThings> based on certain conditions
    }

    public List<Newthings> doSomethingSecond(){
        //uses the list stuff and also increments the static member count for each entry in List<NewThings> based on certain conditions
    }

    public List<Newthings> …

我右键单击>重构>从项目菜单移动,"将所有内容从.../.. /移动到另一个目录">确定选择了另一个文件夹,并且wham,我的所有数据都消失了.我在项目树中做了一个grep -r来找到它,然后找一个.-iname" mydataas "仍然没有出现.没了.

为什么Intellij会这样做？

系统:Windows Vista 32位,Java 6.0.2

关于将字符转换为整数,我有几个问题.我运行下面的代码,将myInt保留为值4:

  char myChar = '4';
  int myInt = myChar - '0';

现在,这种转换是Java自动完成的吗？将ascii值'0'从ascii'4'减去,然后在幕后投射到一个int？这对我来说很困惑,因为当我尝试反向操作时,我必须实际将结果转换为char:

  int anotherInt = 5;
  char newChar = anotherInt + '0'; //gives error

  char newChar = (char)(anotherInt + '0'); //works fine

这是否发生是因为Java会自动将(anotherInt +'0')转换为int,如第一个示例中所示？谢谢.

我正在尝试创建SQL Select,它根据字段返回某个字段的计数.所以,这就是我想要做的.

Select count(distinct id) as TotalCount, -- this will be the total of id
count(distinct id where type='A') as TotalA, -- this will be total when type='A'
count(distinct id where type='B') as TotalB -- This will be total when type = 'B'
from MyTable 

基本上,TotalCount = TotalA + TotalB.

如何在SQL Select语句中实现此目的？谢谢.

我正在尝试学习Java中的继承和接口.我有三个不同的类:Customer,SilverCustomer和GoldCustomer.SilverCustomer和GoldCustomer都扩展了客户.

在申请中,客户获得旅行积分.普通客户获得他们前往积分的里程数.SilverCustomer获得里程*1.5,GoldCustomer获得里程*2分.

当我创建一个普通的客户John时,如何使用方法降级()和升级()在普通客户,silvercustomer和goldcustomer之间切换？

class Testfile {
     public static void main(String[] args) {

         Airline aProgram = new Airline();

         Customer john = new Customer("john", 10001); // 10001 is the id number and the status of a customer is normal

         aProgram.addMembers(john);

    john.update_mileage(12000);
    john.upgrade(); //upgrade John to SilverCustomer
    john.update_mileage(2000);

     aProgram.printAllCustomerMilege(); 
   }
}

我有下表：

CREATE TABLE [dbo].[MyTable](
    [timestamp] [timestamp] NOT NULL,
    [Col1] [varchar](20) NOT NULL,
    [Col2] [varchar](20) NOT NULL,
    [col3] [datetime] NOT NULL,
    [col4] [varchar](10) NOT NULL,
    [Col5] [varchar](10) NOT NULL,
    [Col6] [varchar](10) NOT NULL,
    [Col7] [decimal](38, 20) NOT NULL,
    [Col8] [decimal](38, 20) NOT NULL,
    [Col9] [datetime] NOT NULL,
 CONSTRAINT [MyTable$0] PRIMARY KEY CLUSTERED 
(
    [Col1] ASC,
    [Col2] ASC,
    [Col3] ASC,
    [Col4] ASC,
    [Col5] ASC,
    [Col6] ASC,
    [Col7] ASC
) WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, …

我的班级有一个Enum作为属性.它使用String来设置此attr.有许多枚举类.我怎么能重构它？

public void setType(String s) {  

for (MyEnum1 e : MyEnum1.values()) {  
    if (e.name().equalsIgnoreCase(s))  
    this.type = e;  
}  
for (MyEnum2 e : MyEnum2.values()) {  
    if (e.name().equalsIgnoreCase(s))  
    this.type = e;  
}  
for ...  

提前致谢.

我对这两个查询的结果感到惊讶.我期待两者都一样.我有两个共享一个共同字段的表,但没有设置关系.table(A)有一个字段EventID varchar(10),table(B)有一个字段XXNumber varchar(15).

表B列XXNumber中引用了表A列中的值EventID.即使XXNumber可以容纳15个字符,179K行数据也不会超过10个字符.

所以要求是:

"为了避免重复表B和表A条目,如果XXNumber包含在表A>"事件ID"中,则不应计算它."

要查看我有多少常见记录,我首先运行此查询 - 称之为查询alpha"

SELECT dbo.TableB.XXNumber FROM dbo.TableB WHERE dbo.TableB.XXNumber in
  ( select distinct dbo.TableA.EventId FROM dbo.TableA )

结果是5322行.

以下查询 - 将其称为查询delta,如下所示:

SELECT DISTINCT dbo.TableB.XXNumber, dbo.TableB.EventId
FROM dbo.TableB INNER JOIN dbo.TableA ON dbo.TableB.XXNumber= dbo.TableB.EventId

哈斯返回4308行.

结果行数不应该相同吗？

有没有办法将一些功能移动到谷歌应用程序脚本中的单独文件？目前我的Code.gs如下所示:

function onSubmit(e) {}

function readSpreadsheet(sheet) {}
function writeSpreadsheet(sheet, data) {}

function sendEmail() {}

function helperLogic1() {}
function helperLogic2() {}
function helperLogic3() {}
function helperLogic4() {}

因此,为了使我的代码看起来更好; p ..我想将与电子表格相关的函数移动到spreadsheet.gs电子邮件到email.gs等.所以在移动它们之后,如何从中加载它code.gs？

谢谢

我正在编写一个反应组件，当单击前进handleClickLeft或后退 handleClickRight按钮时，它会向前或向后循环遍历数组。我通过使用模逻辑来做到这一点。我能够让前进按钮handleClickLeft正常工作，但我不知道如何反向操作handleClickRight。这是我的示例代码：

export default class Rooms extends React.Component {
   constructor(props, context) {
      super(props, context);
      this.state = {indexPos: [0, 1, 2]};
      this.state.itemArry = [{room1: 'this is room1'}, {room2: 'this is room2'}, {room3: 'this is room3'}, {room4: 'this is room4'}];

      this.handleClickLeft = this.handleClickLeft.bind(this);
      this.handleClickRight = this.handleClickRight.bind(this);
   }
   render() {   //Using index to show each item in the itemArry
      let firstItem = this.state.indexPos[0]
      let secondItem = this.state.indexPos[1]
      let thirdItem = this.state.indexPos[2]       
      <div>
         <ul>
           <li>this.state.itemArry[firstItem]</li>
           <li>this.state.itemArry[secondItem]</li>
           <li>this.state.itemArry[thirdItem]</li> …