Question

你好，我仍然是linq和编程的新手我正在尝试使用带有linq查询的水晶报告进行报告并将其放入数据表中我使用的是抛出的函数，但是引用的列不在范围内：''..

我正在尝试加入3张桌子。

这是我从互联网上找到的一项功能

 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
                  });

我有一个排队的foreach（T rec in varlist）有没有简单的查询.. ??因为我很困惑加入3张桌子...... 谢谢你的进步

Answer 1

我认为你的问题是：您的查询结果是匿名类型，因此您应该像这样更改您的代码：

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;}
  .....
}

引用的列不在范围内：''

1 个答案: