LINQ：WHERE 子句中的 IF 条件不起作用

Question

我有以下 LINQ 查询，它应该查看表 Products 并向我返回传递参数的记录，这些记录是：搜索词（字符串）和不同“类型”的 3 个布尔值。

   var query = context.Products
                       .Where(a => request.SearchTerm == null || a.Name.Contains(request.SearchTerm))
    .Where(a => (request.isTypeA == false || (a.OrderType == "X" && request.isTypeA == true)) ||
    (request.typeB == false || (a.OrderType == "R" && request.typeB == true))
    || (request.typeC == false || (a.OrderType == "D" && request.typeC == true)))
    .Where (a=> a.OrderType != "U")
    .Where(a => a.IsInactiveFlag == false )
    .OrderBy(a => a.OrderType)
    .Select(c => new ProductType   
        {
            ProductTypeId = c.ProductTypeId,
            IsSelected = false,
            OrderType = c.OrderType,
            Name = c.Name,
            IsInactiveFlag = c.IsInactiveFlag
        });

问题：问题是查询总是通过查看传递的 searchTerm 返回记录，但它没有考虑布尔参数。所以比如说我的搜索参数是：searchTerm = "reference " , isTypeA = false, isTypeB = false 和 isTypeC = true。上面的查询将返回所有不同类型的 searchTerm "reference" 的所有记录，而不仅仅是 TypeC。

在发布这个问题之前我搜索了很多，但没有什么是我遇到的。请让我知道我做错了什么。 谢谢！

Answer 1

您应该在过滤器值的每个测试旁边明确包含/排除关于 OrderType 的二元标准，它用作开关......

  var query = context.Products
                       .Where(a => request.SearchTerm == null || a.Name.Contains(request.SearchTerm))
    .Where(a => (request.isTypeA == false && a.OrderType != "X" ) || (a.OrderType == "X" && request.isTypeA == true)) ||
    (request.typeB == false && a.OrderType != "R" )|| (a.OrderType == "R" && request.typeB == true))
    || (request.typeC == false && a.OrderType != "D" ) || (a.OrderType == "D" && request.typeC == true)))
    .Where (a=> a.OrderType != "U")
    .Where(a => a.IsInactiveFlag == false )
    .OrderBy(a => a.OrderType)
    .Select(c => new ProductType   
        {
            ProductTypeId = c.ProductTypeId,
            IsSelected = false,
            OrderType = c.OrderType,
            Name = c.Name,
            IsInactiveFlag = c.IsInactiveFlag
        });

Answer 2

试试这个

   var query = context.Products
                   .Where(a => request.SearchTerm == null || a.Name.Contains(request.SearchTerm))
.Where(a => (a.OrderType == "X" && request.isTypeA)
|| (a.OrderType == "R" && request.typeB)
|| (a.OrderType == "D" && request.typeC))
.Where (a=> a.OrderType != "U")
.Where(a => a.IsInactiveFlag == false )
.OrderBy(a => a.OrderType)
.Select(c => new ProductType   
    {
        ProductTypeId = c.ProductTypeId,
        IsSelected = false,
        OrderType = c.OrderType,
        Name = c.Name,
        IsInactiveFlag = c.IsInactiveFlag
    });