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你好，我仍然是 linq 和编程的新手，我正在尝试使用带有 linq 查询的水晶报表制作报告，并将其放入数据表中，我正在使用抛出的函数，但引用的列不在范围内：''。 .

我正在尝试加入 3 张桌子。

这是我从网上找到的一个功能

 public DataTable LINQToDataTable<T>(IEnumerable<T> varlist)
        {
            DataTable dtReturn = new DataTable();

            // column names 
            PropertyInfo[] oProps = null;

            if (varlist == null) return dtReturn;

            foreach (T rec in varlist)
            {
                // Use reflection to get property names, to create table, Only first time, others will follow 
                if (oProps == null)
                {
                    oProps = ((Type)rec.GetType()).GetProperties();
                    foreach (PropertyInfo pi in oProps)
                    {
                        Type colType = pi.PropertyType;

                        if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition()
                        == typeof(Nullable<>)))
                        {
                            colType = colType.GetGenericArguments()[0];
                        }

                        dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
                    }
                }

                DataRow dr = dtReturn.NewRow();

                foreach (PropertyInfo pi in oProps)
                {
                    dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue
                    (rec, null);
                }

                dtReturn.Rows.Add(dr);
            }
            return dtReturn;
        }

这是我的 linq

 var id = (from u in myDb.TBL_TRANSAKSI_MKN_MNMs
                  join l in myDb.TBL_DETAIL_TRANSAKSIs on u.ID_NOTA equals l.ID_NOTA
                  //into g1
                  join m in myDb.TBL_MKN_MNMs on l.ID_MKN_MNM equals m.ID_MKN_MNM
                  //into g

                  group new {u,l,m} by new {u.TGL_TRANSAKSI, m.NAMA_MKN_MNM, m.HARGA_JUAL, l.ID_MKN_MNM, u.USERNAME}                      
                  into grp

                  where grp.Key.TGL_TRANSAKSI.Value.Date.Equals(dateTimePicker1.Value.Date)

                  select new
                  {
                      MakanMinum = grp.Key.NAMA_MKN_MNM,
                      HargaJual = grp.Key.HARGA_JUAL,
                      sumStok = grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM),
                      Tanggal = grp.Key.TGL_TRANSAKSI,
                      Jumlah = grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM),
                      Total = grp.Sum(grouptotal => grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM)),
                      Username = grp.Key.USERNAME
                  });

我有一个 inline foreach (T rec in varlist) 是否有任何简单的查询..?? 因为我很困惑加入 3 张桌子......谢谢你的提前

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1 回答 1

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I think your problems is: your query result is anonymous type ,so you should change your code like this:

var id = (from u in myDb.TBL_TRANSAKSI_MKN_MNMs
    where u.GL_TRANSAKSI.Value.Date.Equals(dateTimePicker1.Value.Date)
              join l in myDb.TBL_DETAIL_TRANSAKSIs on u.ID_NOTA equals l.ID_NOTA
              //into g1
              join m in myDb.TBL_MKN_MNMs on l.ID_MKN_MNM equals m.ID_MKN_MNM
              //into g

              group new {u,l,m} by new {u.TGL_TRANSAKSI, m.NAMA_MKN_MNM, m.HARGA_JUAL, l.ID_MKN_MNM, u.USERNAME}                      
              into grp

              select new MyClass
              {
                  MakanMinum = grp.Key.NAMA_MKN_MNM,
                  HargaJual = grp.Key.HARGA_JUAL,
                  sumStok = grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM),
                  Tanggal = grp.Key.TGL_TRANSAKSI,
                  Jumlah = grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM),
                  Total = grp.Sum(grouptotal => grp.Key.HARGA_JUAL * grp.Sum(groupedthing => groupedthing.l.ID_MKN_MNM)),
                  Username = grp.Key.USERNAME
              });


class MyClass
{
  public string MakanMinum {get;set;}
  .....
}
于 2013-06-29T13:51:04.543 回答