C# 查询-LINQ，2个表，Union

这是我的两张桌子：

publicParking(publicParkingID, address, latitude, longtitude, status,
              PricePerHour, maxSpaces, occupiedSpaces, freeSpaces, isOrdered)

及

除ID外，所有列都相同

我需要在LINQ中编写查询，该查询将返回一个按价格排序的表，其中包含所有可用的停车场（

publicParking

/

parkingLot

）-with

status==true

该表应如下所示：

ID地址经纬度状态

我应该进行联合，还是应该更改表以便第一列只调用ID？（而不是

publicParkingID

和

parkingLotID

）

我已经尝试过这个代码，但它不起作用

var union =  
         (from lot in parkingLots
         where lot.status == true
         select lot).Union( from pub in publicParkings
         where pub.status==true
         select pub);

它给出了以下错误：

---

我正在使用LINQPad5和tutorialsteacher的代码编辑器。还有其他选项吗？

要使用

联合

两个结果序列必须包含相同的类型。在您的示例中，外部查询包含

停车场

和内部

公共停车场

可以使用匿名类型解决此问题：

var union =  
     (from lot in parkingLots
     where lot.status == true
     orderby lot.PricePerHour // don't forget ordering
     select new {
           ID = lot.parkingLotID, 
           lot.address, lot.latitude, lot.longitude, lot.status})
    .Union(from pub in publicParkings
     where pub.status==true
     orderby pub.PricePerHour // don't forget ordering
     select new {
           ID = pub.publicParkingID, 
           pub.address, pub.latitude, pub.longitude, pub.status});

但对于进一步的数据处理来说，定制类可能更好：

public class ParkingData
{
    public int ID {get; set;}
    public string Address {get; set;}
    public double Latitude {get; set;}
    public string Longitude {get; set;}
    public bool Status {get; set;}
}

然后像这样询问：

var union =  
     (from lot in parkingLots
     where lot.status == true
     orderby lot.PricePerHour // don't forget ordering
     select new ParkingData {
           ID = lot.parkingLotID, 
           Address = lot.address, 
           Latitude = lot.latitude, 
           Longitude = lot.longitude, 
           Status = lot.status})
    .Union(from pub in publicParkings
     where pub.status==true
     orderby pub.PricePerHour // don't forget ordering
     select new {
     select new ParkingData {
           ID = pub.publicParkingID, 
           Address = pub.address, 
           Latitude = pub.latitude, 
           Longitude = pub.longitude, 
           Status = pub.status});

---

要使用Union，两个结果序列必须包含相同的类型。在您的示例中，外部查询包含

停车场

和内部

公共停车场

可以使用匿名类型解决此问题：

var union =  
     (from lot in parkingLots
     where lot.status == true
     orderby lot.PricePerHour // don't forget ordering
     select new {
           ID = lot.parkingLotID, 
           lot.address, lot.latitude, lot.longitude, lot.status})
    .Union(from pub in publicParkings
     where pub.status==true
     orderby pub.PricePerHour // don't forget ordering
     select new {
           ID = pub.publicParkingID, 
           pub.address, pub.latitude, pub.longitude, pub.status});

但对于进一步的数据处理来说，定制类可能更好：

public class ParkingData
{
    public int ID {get; set;}
    public string Address {get; set;}
    public double Latitude {get; set;}
    public string Longitude {get; set;}
    public bool Status {get; set;}
}

然后像这样询问：

var union =  
     (from lot in parkingLots
     where lot.status == true
     orderby lot.PricePerHour // don't forget ordering
     select new ParkingData {
           ID = lot.parkingLotID, 
           Address = lot.address, 
           Latitude = lot.latitude, 
           Longitude = lot.longitude, 
           Status = lot.status})
    .Union(from pub in publicParkings
     where pub.status==true
     orderby pub.PricePerHour // don't forget ordering
     select new {
     select new ParkingData {
           ID = pub.publicParkingID, 
           Address = pub.address, 
           Latitude = pub.latitude, 
           Longitude = pub.longitude, 
           Status = pub.status});

---

非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。非常感谢。