从数据透视 SQL Server 动态检索数据

Question

Asmx 代码：

            SqlDataReader rdr = cmd.ExecuteReader();
            while (rdr.Read())
            {
                HBPivot_cs thpivot = new HBPivot_cs();
                thpivot.EMPLOYEEID = rdr["EMPLOYEEID"].ToString();
                thpivot.FIRSTDATE = rdr["06/26/2018"].ToString();
                thpivot.SECONDDATE = rdr["06/27/2018"].ToString();
                listhbpivot.Add(thpivot);
            }
            con.Close();

我的数据： 此数据来自 Pivot

EMPLOYEEID     06/26/2018     06/27/2018     06/28/2018     06/29/2018
1              07:00 AM       08:00 AM       07:30 AM       10:00 AM
2              07:01 AM       08:20 AM       07:10 AM       06:00 AM

字段名是动态的...如何使用 rdr.read 检索它 谢谢

Answer 1

1. 在您的 sql server 数据库中创建以下存储过程。

   create procedure dbo.EmploeeDynamicPivot
   as
   begin
   
       set nocount on;
   
       declare
           @columns    as nvarchar(max),
           @query      as nvarchar(max)
   
       select
           @columns    =
           stuff
           ((
                   select
                   distinct
                       ',' + quotename([your_date_column]) 
                   from
                       [your_table]
                   for xml path(''), type
           ).value('.', 'nvarchar(max)'), 1, 1, '')
   
   
       set @query =
       'select
           EMPLOYEEID, ' + @columns + '
       from 
       (
           select
               EMPLOYEEID   ,
               [your_date_column]   ,
               [your_value_column]
           from
               [your_table]
       )
           sourceTable
       pivot 
       (
           sum([your_value_column])
           for [your_date_column] in (' + @columns + ')
       )
           pivotTable'
   
   
       execute(@query);
   
       set nocount off;
   
   end
   

2. 通过以下代码编辑您的 c# 代码。

   var sqlConnection = new SqlConnection([your_connection_string]);
   
   sqlConnection.Open();
   
   var sqlCommand = sqlConnection.CreateCommand();
   
   sqlCommand.CommandType = CommandType.StoredProcedure;
   sqlCommand.CommandText = "EmploeeDynamicPivot";
   
   var rdr = sqlCommand.ExecuteReader();
   
   while (rdr.Read())
   {
       for (int i = 0; i < rdr.FieldCount; i++)
       {
           var value = rdr.GetString(i);
           or
           var value = rdr.GetValue(i);
   
           //do something... 
       }
   }
   ...