快速对比两个list数据集合
小批量、快速对比两个list数据集合
using System.Linq.Expressions;
Main();
void Main()
{
// 对比源集合
var source = GenerateStudent(1, 10000, 1000);
// 目标集合
var target = GenerateStudent(5000, 10000, 1000);
//Expression<>
// 唯一标识比较
Func<Student, Student, bool> keyCompartor = (s, t) => s.Id == t.Id;
// 实体相等比较
Func<Student, Student, bool> entityCompartor = (s, t) => s.Id == t.Id && s.Name.Equals(t.Name) && s.Age == t.Age;
// 新增前准备
Func<Student, Student> insertAction = (s) =>
{
return new Student
{
Id = s.Id,
Name = s.Name,
Age = s.Age,
Operation = "Insert"
};
};
// 更新前准备
Func<Student, Student, Student> updateAction = (s, t) =>
{
t.Name = s.Name;
t.Age = s.Age;
t.Operation = "Update";
return t;
};
// 删除前准备
Func<Student, Student> deleteAction = (t) =>
{
t.Operation = "Delete";
return t;
};
// 去掉相等对象
RemoveDuplicate(source, target, entityCompartor, (s1, s2) => s1.Id == s2.Id, keyCompartor);
// 需要新增的集合
var insertingStudents = GetInsertingEntities(source, target, keyCompartor, insertAction);
// 需要更新的集合
var updatingStudents = GetUpdatingEntities(source, target, keyCompartor, entityCompartor, updateAction);
// 需要删除的集合
var deletingStudents = GetDeletingEntities(source, target, keyCompartor, deleteAction);
// 后续业务
// InsertStudents(insertingStudents);
// UpdateStudents(updatingStudents);
// DeleteStudents(deletingStudents);
Console.WriteLine("");
// 集合去重
void RemoveDuplicate<S, T>(List<S> source, List<T> target, Func<S, T, bool> entityCompartor,
Func<S, S, bool> sourceKeyCompartor, Func<S, T, bool> keyComportor)
{
var sameEntities = source.Where(s => target.Exists(t => entityCompartor(s, t))).ToList();
source.RemoveAll(s => sameEntities.Exists(s2 => sourceKeyCompartor(s, s2)));
target.RemoveAll(t => sameEntities.Exists(s => keyComportor(s, t)));
}
// 获取需要新增的对象集合
List<T> GetInsertingEntities<S, T>(List<S> source, List<T> target, Func<S, T, bool> keyComportor,
Func<S, T> insertAction)
{
var result = new List<T>();
foreach (var s in source)
{
var t = target.FirstOrDefault(x => keyComportor(s, x));
if (t == null)
{
// 目标集合中不存在，则新增
result.Add(insertAction(s));
}
}
return result;
}
// 获取需要更新的对象集合
List<T> GetUpdatingEntities<S, T>(List<S> source, List<T> target, Func<S, T, bool> keyComportor,
Func<S, T, bool> entityCompartor, Func<S, T, T> updateAction)
{
var result = new List<T>();
foreach (var s in source)
{
var t = target.FirstOrDefault(x => keyComportor(s, x));
if (t != null && !entityCompartor(s, t))
{
// 目标集合中存在，但是次要属性不相等，则更新
result.Add(updateAction(s, t));
}
}
return result;
}
// 获取需要删除的对象集合
List<T> GetDeletingEntities<S, T>(List<S> source, List<T> target,
Func<S, T, bool> keyComportor, Func<T, T> deleteAction)
{
var result = new List<T>();
foreach (var t in target)
{
var s = source.FirstOrDefault(x => keyComportor(x, t));
if (s == null)
{
// 源集合中存在，目标集合中需要删除
result.Add(deleteAction(t));
}
}
return result;
}
// 随机生成测试集合
List<Student> GenerateStudent(int minId, int maxId, int maxNumber)
{
var r = new Random();
var students = new List<Student>();
for (int i = 0; i < maxNumber; i++)
{
students.Add(new Student
{
Id = r.Next(minId, maxId),
Name = $"name: {r.Next(1, 10)}",
Age = r.Next(6, 10)
});
}
return students.GroupBy(s => s.Id).Select(s => s.First()).ToList();
}
}
public class Student
{
public int Id { get; set; }
public string Name { get; set; }
public int Age { get; set; }
public string Operation { get; set; }
}
小数量数据 推荐使用linq 以下方法
点击查看代码
List<SRModel> SRlist= db.SRModels.ToList();
List<SRUserInfoDto> Userlist = DataProcessing();
//对比两个集合中的差异并出来。两种方法取。
var srGorup = Userlist.Where(x => !SRlist.Any(a => x.XiaoShouDaiBiaoBianMa == a.XiaoShouDaiBiaoBianMa)).ToList();
var intolist = Userlist.Where(a => !SRlist.Select(b => b.XiaoShouDaiBiaoBianMa).Contains(a.XiaoShouDaiBiaoBianMa)).ToList
IEqualityComparer 接口实现数据不同对比
