带有连接表的 Lambda 表达式

Question

我有以下实体

1. 项目
2. 组件
3. 项目组件

我想写一个类似的方法

GetProjectsByComponentId(int componentId)
{ /* some code*/}

请帮我写一个 lambda 表达式。

来自 EF 生成的架构的片段：

public partial class ProjectComponent
{
    public int ID { get; set; }
    public Nullable<int> ProjectID { get; set; }
    public Nullable<int> ComponentID { get; set; }
    public string Comment { get; set; }

    public virtual Component Component { get; set; }
    public virtual Project Project { get; set; }
}

public partial class Project
{
    public Project()
    {
        this.ProjectComponents = new HashSet<ProjectComponent>();
    }

    public int ID { get; set; }
    public string Description { get; set; }

    public virtual ICollection<ProjectComponent> ProjectComponents { get; set; }
}

public partial class Component
{
    public Component()
    {
        this.ProjectComponents = new HashSet<ProjectComponent>();
    }

    public int ID { get; set; }
    public string Description { get; set; }

    public virtual ICollection<ProjectComponent> ProjectComponents { get; set; }
}

Answer 1

ComponentID 很遗憾，您提供的信息很少，但我会尽力提供帮助。

假设您有 edmx 或代码优先模型：

ctx.Project.Include(p=>p.ProjectComponents).Where(p => p.ProjectComponents.Any(pc=>pc.ComponentID == id)).ToList();

或 SQL

SELCT p.* FROM Project as p
INNER JOIN ProjectComponent as pc ON pc.ProjectID = p.ID
WHERE pc.ProjectID = @ID