与链接/建筑LINQ查询或代替AND [英] Chaining / building LINQ query with an OR instead of AND

问题描述

的编辑，以更清楚的

如果例如我有这种IQueryable的：

 的DateTime theDate =新日期时间（2015，09，30）; 
 
 VAR的查询=从组织在组织
，其中org.DisableOrganisation ==假放;&安培; 
 org.DisableReports ==虚假
选择新的
 {
 OrganisationId = org.OrganisationId 
}; 
  

和后来的方法我想的还是添加到其中，如：

  //检查，看看日期是该月的最后一天。 
如果（theDate.AddDays（1）.DAY == 1）
 {
 //下面的语句引入一个与但我想使这是一个OR。 
查询= query.Where（X => x.Frequency ==M）; 
} 
  

这有效地使我查询...

  VAR的查询=从组织
组织的地方org.DisableOrganisation ==假放;&安培; 
 org.DisableReports ==假放;&安培; 
 org.Frequency ==M
选择新的
 {
 OrganisationId = org.OrganisationId 
}; 
  

但我想让它...

  VAR的查询=从组织
组织在哪里（org.DisableOrganisation ==假放;&安培; 
 org.DisableReports ==假）|| 
 org.Frequency ==M
选择新的
 {
 OrganisationId = org.OrganisationId 
}; 
  

我如何去代替，使这一个OR？

PS 不能使用PredicateBuilder，因为它本质上是具有的EntityFramework的依赖关系（≥6.0.2），我坚持使用LinqKit EF 4.3.1

解决：感谢到D士丹利（说实话，我以前曾使用过这种形式的解决方案，我只是忘了）

 的DateTime theDate =新日期时间（2015，09，30）; 
布尔isEndOfMonth = theDate.AddDays（1）.DAY == 1; 
 
 VAR的查询=从组织在组织
，其中（org.DisableOrganisation ==假放;&安培; 
 org.DisableReports ==假）|| 
（isEndOfMonth&安培;&安培; 
 pr.ProfileType ==L&放大器;&安培; 
 pr.Frequency ==M）
选择新的
 { 
 OrganisationId = org.OrganisationId 
}; 
  

解决方案

您无法通过链接做到这一点 - 你将不得不使用某种形式的表达式生成器，或者只是建立在你原来的过滤器：

  VAR天= theDate.AddDays（ 1天; 
 
 VAR的查询=从组织在组织
，其中（org.DisableOrganisation ==假放;&安培; 
 org.DisableReports ==假）|| 
（==天1和;&放大器; 
 org.ProfileType ==L，&放大器;&放大器; 
 org.Frequency ==M）
选择新
 {
 OrganisationId = org.OrganisationId 
}; 
  

Edited to be clearer.

If for example I have this IQueryable:

DateTime theDate = new DateTime(2015, 09, 30);

var query = from org in Organisations
            where org.DisableOrganisation == false &&
              org.DisableReports == false
            select new
            {
                OrganisationId = org.OrganisationId
            };

and later in the method I want to add an OR to it, e.g.

// Check to see if the date is the last day of the month.
if (theDate.AddDays(1).Day == 1)
{
    // The following statement introduces an AND but I want to make this an OR.
    query = query.Where(x => x.Frequency == "M");
}

This effectively makes my query...

var query = from org in Organisations
            where org.DisableOrganisation == false &&
              org.DisableReports == false &&
              org.Frequency == "M"
            select new
            {
                OrganisationId = org.OrganisationId
            };

but I want to make it...

var query = from org in Organisations
            where (org.DisableOrganisation == false &&
              org.DisableReports == false) ||
              org.Frequency == "M"
            select new
            {
                OrganisationId = org.OrganisationId
            };

How do I go about making this an OR instead of an AND ?

P.S. Cannot use PredicateBuilder as it is essentially LinqKit which has a dependency of EntityFramework (≥ 6.0.2), I'm stuck using EF 4.3.1

SOLVED: Thanks to D Stanley (To be honest I had used this form of solution before, I simply forgot about it).

DateTime theDate = new DateTime(2015, 09, 30);
bool isEndOfMonth = theDate.AddDays(1).Day == 1;

var query = from org in Organisations
            where (org.DisableOrganisation == false &&
              org.DisableReports == false) ||
              (isEndOfMonth &&
               pr.ProfileType == "L" && 
               pr.Frequency == "M")
            select new
            {
                OrganisationId = org.OrganisationId
            };

解决方案

You can't do it by chaining - you'll have to use some sort of expression builder, or just build that in your original filter:

var day = theDate.AddDays(1).Day;

var query = from org in Organisations
            where (org.DisableOrganisation == false &&
                   org.DisableReports == false) ||
                  (day == 1 &&
                   org.ProfileType == "L" && 
                   org.Frequency == "M")
            select new
            {
                OrganisationId = org.OrganisationId
            };

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