如果否则条件在linq查询中不起作用

本文介绍了如果否则条件在linq查询中不起作用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我有这个代码： var vr =（ 来自 context.GRI_Package // where（ISSTUDENT == true？s.StudentID == StudentUserID：s.TutorUserID == TutorUserID） // where（ISSTUDENT == true？s .StudentID == StudentUserID：（s.TutorUserID == TutorUserID&& s.StudentID == StudentUserID ）） 其中（ISSTUDENT == true ？（s.TutorUserID = = 0 || s.StudentID == StudentUserID）:( s.TutorUserID == TutorUserID&& s.StudentID == StudentUserID）） // 其中s.TutorUserID == TutorUserID&& s.StudentID == StudentUserID 选择 new GetSessionpackageInfo { PackageID = s.PackageID， }）。ToList（）; vr。转储（）; 这里如果其他条件不是wokring有没有语法错误？ 请帮帮我 我尝试了什么： 我试过这个条件 where（ISSTUDENT == true？（s.TutorUserID == 0 || s.StudentID == StudentUserID）:( s.TutorUserID == TutorUserID&& s.StudentID == StudentUserID））解决方案 问题是您正在尝试在where子句中使用过程控制流逻辑。您需要了解WEHRE子句中的内容是布尔表达式而不是语句。 我将解释您之前的一个&更简单的尝试，你已经注释掉了。你有两个选择。对你来说更自然的可能就是在这样的C＃代码中做一个IF： var query = context.GRI_Package; if （ISSTUDENT） { query = query.Where（s = > ; s.StudentID == StudentUserID）; } else { query = query.Where（s = > s.TutorUserID == TutorUserID）; } var vr = query.Select（s = > new GetSessionpackageInfo {PackageID = s.PackageID}）。ToList（）; 或者你可以拥有全部where子句但它必须是布尔表达而不是声明： var vr =（ 来自 s context.GRI_Package 其中（ISSTUDENT == true && s.StudentID == StudentUserID） ||（ISSTUDENT == false && s.TutorUserID == TutorUserID） 选择 new GetSessionpackageInfo { PackageID = s.PackageID，}）。ToList（）; I have this code :var vr = (from s in context.GRI_Package //where (ISSTUDENT == true ? s.StudentID == StudentUserID : s.TutorUserID == TutorUserID) //where (ISSTUDENT == true ? s.StudentID == StudentUserID : (s.TutorUserID == TutorUserID && s.StudentID == StudentUserID)) where (ISSTUDENT == true ? (s.TutorUserID == 0 || s.StudentID == StudentUserID) : (s.TutorUserID == TutorUserID && s.StudentID == StudentUserID)) //where s.TutorUserID == TutorUserID && s.StudentID == StudentUserID select new GetSessionpackageInfo { PackageID = s.PackageID,}).ToList();vr.Dump();here if else condition is not wokring is there any syntax mistake ?please help meWhat I have tried:I tried this conditionwhere (ISSTUDENT == true ? (s.TutorUserID == 0 || s.StudentID == StudentUserID) : (s.TutorUserID == TutorUserID && s.StudentID == StudentUserID)) 解决方案 The problem is that you are trying to use procedural control flow logic in the where clause. You need to understand that what's in the WEHRE clause is a boolean expression not a statement.I will explain on one of your earlier & simpler attempts, which you have commented out. You have two options. More natural for you would be maybe do an IF in the C# code like this:var query = context.GRI_Package;if (ISSTUDENT){ query = query.Where(s => s.StudentID == StudentUserID);}else{ query = query.Where(s => s.TutorUserID == TutorUserID);}var vr = query.Select(s => new GetSessionpackageInfo {PackageID = s.PackageID}).ToList();Or you can have is all in the where clause but then it needs to be a boolean expresson and not a statement:var vr = (from s in context.GRI_Package where (ISSTUDENT == true && s.StudentID == StudentUserID) || (ISSTUDENT == false && s.TutorUserID == TutorUserID) select new GetSessionpackageInfo { PackageID = s.PackageID, }).ToList(); 这篇关于如果否则条件在linq查询中不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！