我設置的參數如何基於使用LINQ和Entity Framework

Question

條件這是我的代碼：

await ctx.Education.AsNoTracking() 
     .Where(e => e.EmployeeNumber == employeeNumber) 
     .Select(e => new EducationDTO { 
       Id = e.EducationID, 
       StartDate = DbFunctions.CreateDateTime(e.EducationEntryYear , 1, 1, 0, 0, 0) ?? DateTime.Now, 
       EndDate = DbFunctions.CreateDateTime(e.EducationGraduationYear, 1, 1, 0, 0, 0), 
     }) 
     .ToListAsync().ConfigureAwait(false); 

在某些情況下，「e.EducationEntryYear」爲0，結果返回此異常Conversion failed when converting date and/or time from character string.

什麼是有第一個參數作爲本年度最簡單的方法，如果e.EducationEntryYear是0

Answer 1

使用條件（?）運算符。

await ctx.Education.AsNoTracking() 
     .Where(e => e.EmployeeNumber == employeeNumber) 
     .Select(e => new EducationDTO { 
       Id = e.EducationID, 
       StartDate = DbFunctions.CreateDateTime(e.EducationEntryYear == 0 ? DateTime.Now.Year : e.EducationEntryYear, 1, 1, 0, 0, 0) ?? DateTime.Now, 
       EndDate = DbFunctions.CreateDateTime(e.EducationGraduationYear, 1, 1, 0, 0, 0), 
     }) 
     .ToListAsync().ConfigureAwait(false); 

Answer 2

如果您目前有

e.EducationEntryYear 

與

e.EducationEntryYear == 0 ? System.DateTime.Now.Year : e.EducationEntryYear