c# - 导出到 csv - Linq 查询

Question

我在 linq 中有一个像这样查询数据库表的类，问题是:如何将该数据导出到 csv？我已经尝试了建议的链接并且我正在使用 linq2csv 并且仍然想知道如何按他们的顺序获取列？谢谢!

var usr = from usr in db.User 
select new { usr.UserName, usr.Dept, usr.Name)
MainListView.DataSource = usr; 
MainListView.DataBind();

CsvFileDescription outputFileDescription = new CsvFileDescription
                {
                    SeparatorChar = ',',
                    FirstLineHasColumnNames = true,
                    FileCultureName = "en-US"
                };

                CsvContext cc = new CsvContext();
               string finalPath = mypath + "usr_" + DateTime.Now.ToString  ( "yyyyMMddhhmmssfff" ) + ".csv";
                cc.Write( usr, finalPath, outputFileDescription );

Answer 1

为了控制排序顺序，您必须定义一个具有如下属性的类

public class User
{
    [CsvColumn(FieldIndex = 1)]
    public string UserName { get; set; }

    [CsvColumn(FieldIndex = 2)]
    public string Dept { get; set; }

    [CsvColumn(FieldIndex = 3)]
    public string Name { get; set; }
}

然后您更改您的 linq 查询以使用此类，例如

string mypath = @".\";  

var usr = (from u in db.User select new User 
               { 
                   UserName = u.UserName, 
                   Dept     = u.Dept    ,  
                   Name     = u.Name 
               }
          );

CsvFileDescription outputFileDescription = new CsvFileDescription
    {
        SeparatorChar = ',',
        FirstLineHasColumnNames = true,
        FileCultureName = "en-US"
    };

CsvContext cc = new CsvContext();
string finalPath = mypath + "usr_" + DateTime.Now.ToString("yyyyMMddhhmmssfff" ) + ".csv";
cc.Write( usr, finalPath, outputFileDescription );