LINQ to SQL中的子串和case语句

Question

我正在将SQL转换为LINQ。有人可以帮助如何在LINQ中实现像下面的子字符串和case语句。

SELECT p.goalcommitment, 
     g.goalmeasurement, 
     CASE g.goalmeasurement 
      WHEN 'Count' THEN CAST(p.goalcommitmentnumber AS VARCHAR) 
      WHEN 'Currency' THEN '$' + CAST(p.goalcommitmentcurrency AS VARCHAR) 
      WHEN 'Percentage' THEN RTRIM(CAST(p.goalcommitmentpercentage AS VARCHAR)) + '%' 
      ELSE p.pamwb_goalcommitment 
     END AS goalcommitment, 
     SUBSTRING(p.domainname, CHARINDEX('\', p.domainname, 0) + 1, LEN(p.domainname) - CHARINDEX('\', p.domainname, 0))  
FROM Filtered_psp p 
JOIN Filtered_goalsubtype g 
ON g.goalsubtypeid = p.goalsubtype 

Answer 1

这是你的SQL将如何看起来像在LINQ：

var query = from p in Filtered_psp 
      join g in Filtered_goalsubtype on p.goalsubtype equals g.goalsubtypeid 
      let slashLocation = p.domainname.IndexOf(@"\") 
      select new 
      { 
       Field1 = p.goalcommitment, 
       Field2 = g.goalmeasurement, 
       Field3 = (p.goalmeasurement == "Count" ? p.goalcommitmentnumber.ToString() : 
          p.goalmeasurement == "Currency" ? "$" + p.goalcommitmentnumber.ToString() : 
          p.goalmeasurement == "Percentage" ? p.goalcommitmentnumber.ToString() + "%" : p.pamwb_goalcommitment), 
       Field4 = slashLocation == -1 ? (p.domainname : p.domainname.Substring(slashLocation + 1, p.domainname.Length - slashLocation - 1))) 
      };