我如何加入OR条件

这是我的LINQ代码:

from b in dbContext.SAPBillOfMaterials 
from t in dbContext.AUXComponentTypes
where t.ParentId == b.Parent.Id && 
t.MaterialType == b.Component.MaterialType && 
(t.ComponentCategoryCode == null || t.ComponentCategoryCode == b.Component.ComponentCategoryCode)
    select new
    {
      ComponentCode = b.Component.Model_ComponentCode,
      Grid = b.Component.Grid ,
      ComponentType = t.ComponentType,
      ConfigurationId = configId,
      ParentSKUId = b.Parent.Id ,
      SKUId = b.Component.Id 
     };

这是LINQ到实体的翻译:

    SELECT 
    [Extent2].[ParentId] AS [ParentId], 
    [Extent4].[Model_ComponentCode] AS [Model_ComponentCode], 
    [Extent4].[Grid] AS [Grid], 
    [Extent2].[ComponentType] AS [ComponentType], 
    [Extent1].[Parent_Id] AS [Parent_Id], 
    [Extent1].[Component_Id] AS [Component_Id]
    FROM    [dbo].[SAPBillOfMaterial] AS [Extent1]
    INNER JOIN [dbo].[AUXComponentTypes] AS [Extent2] ON [Extent1].[Parent_Id] = [Extent2].[ParentId]
    INNER JOIN [dbo].[SAPMasterMaterialSKU] AS [Extent3] ON ([Extent2].[MaterialType] = [Extent3].[MaterialType]) 
AND ([Extent1].[Component_Id] = [Extent3].[Id]) 
**AND ([Extent2].[ComponentCategoryCode] = [Extent3].[ComponentCategoryCode])**
    LEFT OUTER JOIN [dbo].[SAPMasterMaterialSKU] AS [Extent4] ON [Extent1].[Component_Id] = [Extent4].[Id]

因此，它完全忽略了连接中的OR条件:

(t。ComponentCategoryCode == null || t.p onentcategorycode ==b.Component.ComponentCategoryCode)

谁能告诉我为什么或我做错了什么?

下面是我的模型的简化版本:

public class AUXComponentType
{
    [Key]
    public int Id { get; set; }
    [Required, ForeignKey("SAPMasterMaterialSKU")]
    public int ParentId { get; set; }
    public virtual SAPMasterMaterialSKU SAPMasterMaterialSKU { get; set; }
    [Required,StringLength(4)]
    public string MaterialType { get; set; }
    [Required, StringLength(1)]
    public string ComponentType { get; set; }
    [Required, StringLength(20)]
    public string ComponentCategoryCode { get; set; }
}
public class SAPBillOfMaterial
{
    [Key, Column(Order = 1)]
    public int Id { get; set; }
    [InverseProperty("SAPBOMChilds"), Column(Order = 2)]
    public virtual SAPMasterMaterialSKU Parent { get; set; }
    [InverseProperty("SAPBOMs"), Column(Order = 3)]
    public virtual SAPMasterMaterialSKU Component { get; set; }
    public decimal Quantity { get; set; }
}
public class SAPMasterMaterialSKU
{
    [Key]
    public int Id { get; set; }
    [Required,MaxLength(18)]
    public string Model_ComponentCode { get; set; }
    [MaxLength(8)]
    public string Grid { get; set; }
    [Required,MaxLength(4)]
    public string MaterialType { get; set; }

    [Required, MaxLength(20)]
    public string ComponentCategoryCode { get; set; }
    public virtual ICollection<SAPBillOfMaterial> SAPBOMChilds { get; set; }
    public virtual ICollection<SAPBillOfMaterial> SAPBOMs { get; set; }
    public virtual ICollection<AUXComponentType> AUXComponentTypes { get; set; }
}