C# Remove first empty line in View

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• C# - Adding condition to func results in stack overflow exception

  I have a func as part of specification class which sorts the given iqueryable

  Func<IQueryable<T>, IOrderedQueryable<T>>? Sort { get; set; }
  

  When i add more than one condition to the func like below , it results in stack overflow exception.

  spec.OrderBy(sc => sc.Case.EndTime).OrderBy(sc => sc.Case.StartTime);
  

  The OrderBy method is implemented like this

  public ISpecification<T> OrderBy<TProperty>(Expression<Func<T, TProperty>> property)
      {
          _ = Sort == null ? Sort = items => items.OrderBy(property) : Sort = items => Sort(items).ThenBy(property);
          return this;
      }
  

  Chaining or using separate lines doesn't make a difference.

  This problem gets resolved if I assign a new instance of the specification and set it's func, but i don't want to be assigning to a new instance everytime. Please suggest what am i missing here and how to reuse the same instance (if possible).
• How to projection fields for a dictionary (C#, MongdoDB)

  I am trying my luck here, I have a model which is like the following

  public class RowData : BaseBsonDefinition
  {
  .
    [BsonExtraElements]
    [BsonDictionaryOptions(DictionaryRepresentation.ArrayOfDocuments)]
    public Dictionary<string, object> Rows { get; set; } = new(StringComparer.OrdinalIgnoreCase);
  .
  }
  
  

  In result, the schema in the MongoDB looks like

  {
  "_id": {
      "$binary": {
        "base64": "HiuI1sgyT0OZmcgGUit2dw==",
        "subType": "03"
      }
    },
    "c1": "AAA",
    "c8": "Fully Vac",
    "c10": "",
  }
  

  Those c1, c8 and c10 fields are keys from the dictionary, my question is how to dynamic project those fields?

  I tried

  Builders<RowData>.Projection.Exclude(p => "c1")
  

  It seems the MongoDB driver can not handle a value directly.

  Anyone could point me in the correct direction?

  Thanks,
• How do I add new DataSource to an already Databinded CheckBoxList

  i'm building a web form that show Database's item(Tables, Rows, FK,...)

  I have a CheckBoxList of Tables (chkListTable) which will show a new CheckBoxList of Rows (chkListRow) everytime I SelectedIndexChanged from chkListTable. The problem is i can show the items from chkListTable with 1 selected item. But i don't know how to show chkListRow if multiple item from chkListTable are selected.

  Here are my codes:

  aspx:

  <div>
               <asp:Label ID="Label2" runat="server" Text="Table: "></asp:Label>
               <asp:CheckBoxList ID="chkListTable" runat="server"
                   DataTextField="name"
                   DataValueFeild="name"
                   AutoPostBack="true"
                   OnSelectedIndexChanged="chkListTable_SelectedIndexChanged">
               </asp:CheckBoxList>
          </div>
          <div>
               <asp:CheckBoxList ID="chkListRow" runat="server"
               DataTextField="COLUMN_NAME"
               DataValueField="COLUMN_NAME"
               RepeatDirection="Horizontal">
               </asp:CheckBoxList>
          </div>
  

  aspx.cs:

  protected void chkListTable_SelectedIndexChanged(object sender, EventArgs e)
      {
          tableName.Clear();
          
          foreach (ListItem item in chkListTable.Items)
          {
              if(item.Selected)
              {
                  tableName.Add(item.Text.Trim());
              }    
          }
  
          for(int i = 0; i < tableName.Count; i++)
          {
              String query = "USE " + dbname +
                  " SELECT * FROM information_schema.columns" +
                  " WHERE table_name = '" + tableName[i] + "'" +
                  " AND COLUMN_NAME != 'rowguid'";
              chkListRow.DataSource = Program.ExecSqlDataReader(query);
              chkListRow.DataBind(); 
              Program.conn.Close();
          }
      }
  

  Program.cs:

  public static bool Connect()
      {
          if (Program.conn != null && Program.conn.State == ConnectionState.Open)
              Program.conn.Close();
          try
          {
              Program.conn.ConnectionString = Program.constr;
  
              Program.conn.Open();
  
              return true;
          }
  
          catch (Exception e)
          {
              return false;
          }
      }
  
      public static SqlDataReader ExecSqlDataReader(String query)
      {
          SqlDataReader myreader;
          SqlCommand sqlcmd = new SqlCommand(query, Program.conn);
          sqlcmd.CommandType = CommandType.Text;
          if (Program.conn.State == ConnectionState.Closed) Program.conn.Open();
          try
          {
              myreader = sqlcmd.ExecuteReader();
              return myreader;
              myreader.Close();
          }
          catch (SqlException ex)
          {
              Program.conn.Close();
              return null;
          }
      }
  

  I want my display to be like this:

  [x]Table1 [x]Table2 [ ]Table3
  [ ]Row1(Table1) [ ]Row2(Table1) [ ]Row3(Table1)
  [ ]Row1(Table2) [ ]Row2(Table2)