LINQ分组或拆分
我在做一些可能很简单的事情时遇到了问题 我的LINQ查询将返回一个包含10个对象的结果集 比如:LINQ分组或拆分,linq,c#-4.0,entity-framework-4,Linq,C# 4.0,Entity Framework 4,我在做一些可能很简单的事情时遇到了问题 我的LINQ查询将返回一个包含10个对象的结果集 比如: Name: Bill, Action: aaa, Id: 832758 Name: Tony, Action: aaa, Id: 82fd58 Name: Bill, Action: bbb, Id: 532758 Name: Tony, Action: bbb, Id: 42fd58 我需要做的是,对这些行进行分组,以便只有两行,即每个名称一行,但将带有“Action:bbb”的行移到另一列中。
Name: Bill, Action: aaa, Id: 832758
Name: Tony, Action: aaa, Id: 82fd58
Name: Bill, Action: bbb, Id: 532758
Name: Tony, Action: bbb, Id: 42fd58
我需要做的是,对这些行进行分组,以便只有两行,即每个名称一行,但将带有“Action:bbb”的行移到另一列中。因此,输出将是:
Name: Bill, Action: aaa, Action_2: bbb, Id: 832758, Id_2: 532758
Name: Tony, Action: aaa, Action_2: bbb, Id: 82fd58, Id_2: 42fd58
谁能向我解释一下我该怎么做
干杯我认为没有真正简单的方法。不过,我知道了这一点,这可能会让你开始:
var myData = new []
{
new { Name = "Bill", Action="aaa", Id = "832758" },
new { Name = "Tony", Action="aaa", Id = "82fd58" },
new { Name = "Bill", Action="bbb", Id = "532758" },
new { Name = "Tony", Action="bbb", Id = "42fd58" }
};
// group all the Names together
var result = from m in myData
group m by m.Name into names
orderby names.Key
select names;
// go through each Name group and create the output string to store in sbLines
var sbLines = new StringBuilder();
foreach (var name in result)
{
var sb = new StringBuilder();
sb.AppendFormat("Name: {0}, ", name.Key);
int count = 1;
foreach (var item in name)
{
if(count > 1)
sb.AppendFormat("Action_{0}: {1}, ", count, item.Action);
else
sb.AppendFormat("Action: {0}, ", item.Action);
count++;
}
count = 1;
foreach (var item in name)
{
if(count > 1)
sb.AppendFormat("Id_{0}: {1}, ", count, item.Id);
else
sb.AppendFormat("Id: {0}, ", item.Id);
count++;
}
sbLines.Append(sb.ToString().Trim(new char[] { ' ',',' }));
sbLines.Append(Environment.NewLine);
}
Console.WriteLine(sbLines.ToString());
在此处运行它:
上面的查询假设每个名称只有两行;如果每个名称有多行,您可以使用
.Skip(1)执行第二个操作/Id
值。使用(1)
而不是.Last()
可以发布返回原始数据的LINQ查询吗?每个名称只有2行,还是数字未知?
var myData = new []
{
new { Name = "Bill", Action="aaa", Id = "832758" },
new { Name = "Tony", Action="aaa", Id = "82fd58" },
new { Name = "Bill", Action="bbb", Id = "532758" },
new { Name = "Tony", Action="bbb", Id = "42fd58" }
};
var result = myData
.GroupBy(x=>x.Name)
.Select(g=>new
{
Name = g.Key,
Action = g.First().Action,
Action_2 = g.Last().Action,
Id = g.First().Id,
Id_2 = g.Last().Id
});