在实体框架核心中执行LINQ，以加载子相关实体数据

using Microsoft.EntityFrameworkCore;

// 定义实体类
public class ParentEntity
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<ChildEntity> Children { get; set; }
}

public class ChildEntity
{
    public int Id { get; set; }
    public string Name { get; set; }
}

// 定义DbContext
public class MyDbContext : DbContext
{
    public DbSet<ParentEntity> Parents { get; set; }
    public DbSet<ChildEntity> Children { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("连接字符串");
    }
}

// 查询并加载子相关实体数据
using (var context = new MyDbContext())
{
    var parent = context.Parents
        .Include(p => p.Children) // 使用Include方法加载Children导航属性
        .FirstOrDefault(p => p.Id == parentId);

    // 可以访问parent.Children获取加载的子实体数据
}