LINQ內部連接4個表（將SQL轉換爲C＃LINQ）

Question

你好。我想加盟4個表：

tStore（STOREID，STORE_NAME）

tSection（SectionID，SECTION_NAME）

tSectionSqft（SectionSqftID，STOREID，SectionID，平方英尺）

tSectionForwardSelling（SectionForwardSellingID ，店號，節號，金額，日期）

我想查詢給我結果：

STORE_NAME，SECTION_NAME，平米，金額

我需要這個SQL查詢轉換爲C＃LINQ：

SELECT 
    tStore.Store_Name, 
    tSection.Section_Name, 
    tSectionSqft.Sqft, 
    tSectionForwardSelling.Amount 
FROM tSection 
INNER JOIN tSectionForwardSelling 
     ON tSection.SectionID = tSectionForwardSelling.SectionID 
INNER JOIN tSectionSqft 
     ON tSection.SectionID = tSectionSqft.SectionID 
INNER JOIN tStore 
     ON tSectionForwardSelling.StoreID = tStore.StoreID 
     AND tSectionSqft.StoreID = tStore.StoreID 

我想對我自己的，但每次LINQ給了我錯誤的結果。

Answer 1

你應該做這樣的事情（只是一個片段）：

var result = from s in tSection join ss in tSectionForwardSelling on s.SectionId equals ss.sectionID 
     join sq in tSectionSqft on s.SectonId equals sq.SectionID 
     join st in stores on ...... 
     select new {field1 = s.Field1 
        field2 = sq.FieldName,...} 

Answer 2

var queryResult = from a in tSection 
      join b in tSectionForwardSelling on a.SectionID equals b.SectionID 
      join c in tSectionSqft on a.SectionID equals c.SectionID 
      join d in tStore on new { u1 = b.SectionID , u2 = c.SectionID } equals new { u1 = d.SectionID , u2 = d.SectionID } 
      select new { d.Store_Name, a.Section_Name, c.Sqft, b.Amount }; 

Answer 3

試試這個：

public class RetrieveData 
{ 
    public string StoreName { get; set; } 
    public string SectionName { get; set; } 
    public int Sqft { get; set; } 
    public int Amount { get; set; } 
} 

public void Method(tStore store) 
{ 
    // Store_Name, Section_Name, Sqft, Amount 

    var list = from se in Context.Sections 
       join fs in tSectionForwardSelling on se.SectionID equals fs.SectionID 
       join sqft in tSectionSqft on se.SectionID equals sqft.SectionID 
       join st in tStore on new { u1 = fs.StoreID , u2 = st.StoreID } equals new { u1 = sqft.StoreID , u2 = st.StoreID } 
       select new RetrieveData() { 
        StoreName = st.Store_Name, 
        SectionName = se.Section_Name, 
        Sqft = sqft.Sqft, 
        Amount = fs.Amount }; 
} 

我想給join到@Nazmul的一部分功勞。