使用LINQ将记录展平为父/子对象。不需要重复数据

// 假设有一个包含父对象和子对象的数据表
var records = new List<Record>
{
    new Record { ParentId = 1, ParentName = "Parent 1", ChildId = 1, ChildName = "Child 1" },
    new Record { ParentId = 1, ParentName = "Parent 1", ChildId = 2, ChildName = "Child 2" },
    new Record { ParentId = 2, ParentName = "Parent 2", ChildId = 3, ChildName = "Child 3" },
    new Record { ParentId = 2, ParentName = "Parent 2", ChildId = 4, ChildName = "Child 4" }
};

// 使用LINQ将记录展平为父/子对象
var flattenedRecords = from parent in records
                       join child in records on parent.ParentId equals child.ParentId
                       select new FlattenedRecord
                       {
                           ParentId = parent.ParentId,
                           ParentName = parent.ParentName,
                           ChildId = child.ChildId,
                           ChildName = child.ChildName
                       };

// 输出展平后的父/子对象
foreach (var record in flattenedRecords)
{
    Console.WriteLine($"Parent: {record.ParentName} ({record.ParentId}), Child: {record.ChildName} ({record.ChildId})");
}