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C#Linq列名为两个单词(去年)或带前导零的数字(01)

linq-to-sql linq c#

Joe Belladonna · 技术社区 · 6 年前

从存储过程中,我获得了列名称如下的数据 Last year 和 01 ,则, 02 ,则, 03 。。。在第一种情况下,列名由两个单词组成,在其他情况下,列名是前导为零的数字。我知道这个存储过程的设计者做了一些愚蠢的事情,但是 我无法更改存储过程。 我的目标是按列对数据进行分组,然后按这些奇怪的列名求和,但VS2017不喜欢这样。我做了以下工作:

var list = (from r in dataFromSP
    group r by new { r.TicketTypeName, r.PaymentMonth } into grp
    select new
    {
        grp.Key.TicketTypeName,
        grp.Key.PaymentMonth,
        LastYear = grp.Sum(t => (decimal?)t.Last year),
        M01 = grp.Sum(t => (decimal?)t.01),
        M02 = grp.Sum(t => (decimal?)t.02),
        M03 = grp.Sum(t => (decimal?)t.03),
        M04 = grp.Sum(t => (decimal?)t.04),
        M05 = grp.Sum(t => (decimal?)t.05),
        M06 = grp.Sum(t => (decimal?)t.06),
        M07 = grp.Sum(t => (decimal?)t.07),
        M08 = grp.Sum(t => (decimal?)t.08),
        M09 = grp.Sum(t => (decimal?)t.09),
        M10 = grp.Sum(t => (decimal?)t.10),
        M11 = grp.Sum(t => (decimal?)t.11),
        M12 = grp.Sum(t => (decimal?)t.12)
}).ToList<dynamic>();

我不知道如何将LINQ与这些奇怪的列名一起使用。我尝试了[],

LastYear = grp.Sum(t => (decimal?)t.[Last year]),
M01 = grp.Sum(t => (decimal?)t.[01]),

并带有“”,

LastYear = grp.Sum(t => (decimal?)t."Last year"),
M01 = grp.Sum(t => (decimal?)t."01"),

但是没有运气。有没有可能在LINQ中使用这些奇怪的列名,有没有办法解决这种奇怪的情况?

2 回复 | 直到 6 年前

MichaÅ Å»oÅnieruk 6 年前

使用映射类并将您的特殊列名放入列属性中,如下所示。然后您就可以毫无问题地使用字段名。

[Table(Name="TableNumbers")]
public class Numbers
{
    [Column(Name="Last year")]
    public int LastYear;

    [Column(Name="01")]
    public int First;
}

资料来源: https://msdn.microsoft.com/en-us/library/bb386983(v=vs.100).aspx

Joe Belladonna 6 年前

我已经设法解决了这个问题。玛瑙帮我指明了正确的方向,所以谢谢你玛瑙。

这就是帮助我的原因:

var list = (from r in dataFromSP
    group r by new { r.TicketTypeName, r.PaymentMonth } into grp
    select new
    {
        grp.Key.TicketTypeName,
        grp.Key.PaymentMonth,
        LastYear = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["Last year"]),
        M01 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["01"]),
        M02 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["02"]),
        M03 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["03"]),
        M04 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["04"]),
        M05 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["05"]),
        M06 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["06"]),
        M07 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["07"]),
        M08 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["08"]),
        M09 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["09"]),
        M10 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["10"]),
        M11 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["11"]),
        M12 = grp.Sum(t => (decimal?)((IDictionary<String, Object>)t)["12"]),
}).ToList<dynamic>();