how to make null values and empty element in xml have open tags and close tag? Asp.net web api 2

Question

i am making a web api and i want to make the open tags and close tags for empty elements and null values. i am using C# and visual basic to code.

My Questions: How to make open tags and close tags for null values and empty elements in xml format with C#?

result outcome:

   <UserId>32</UserId>  
   <Name>Emily</Name>  
   <Mobile>47542942</Mobile>  
   <Age/>  
   <Date i:nil="true"/>  
   <UserId>12</UserId>  
   <Name>Peter</Name>  
   <Mobile>102352134</Mobile>  
   <Age/>  
   <Date i:nil="true"/>  

expect result outcome:

   <UserId>32</UserId>  
   <Name>Emily</Name>  
   <Mobile>47542942</Mobile>  
   <Age></Age>  
   <Date></Date>  
   <UserId>12</UserId>  
   <Name>Peter</Name>  
   <Mobile>102352134</Mobile>  
   <Age></Age>  
   <Date></Date>  

OR

   <UserId>32</UserId>  
   <Name>Emily</Name>  
   <Mobile>47542942</Mobile>  
   <Age>null</Age>  
   <Date>null</Date>  
   <UserId>12</UserId>  
   <Name>Peter</Name>  
   <Mobile>102352134</Mobile>  
   <Age>null</Age>  
   <Date>null</Date>  

My code:

   public IHttpActionResult GetAll()  
           {  
               List<TestClass> draft = new List<TestClass>();  
               string mainconn = ConfigurationManager.ConnectionStrings["myconn"].ConnectionString;  
               SqlConnection sqlconn = new SqlConnection(mainconn);  
               string sqlquery = "SELECT UserID, Name, Mobile, Age, Date FROM tblTest";  
               sqlconn.Open();  
               SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);  
               SqlDataReader sdr = sqlcomm.ExecuteReader();  
               while (sdr.Read())  
               {  
                     draft.Add(new TestClass()  
                     {  
                           UserId = sdr.GetString(0),  
                           Name = sdr.GetString(1),  
                           Mobile = sdr.GetString(2),  
                           Age = (sdr.GetValue(3) != DBNull.Value) ? Convert.ToInt32(sdr.GetValue(3)) : 0,  
                           Date = (sdr.GetValue(4) != DBNull.Value) ? Convert.ToDateTime(sdr.GetValue(4)) : (DateTime)sdr.GetValue(4)  
                     });  
               }  
               return Ok(draft);  
           }  

Is this possible?

Answer 1

You can choice to pass Age and Date as string fields and setting it with constant string value. For example:
while (sdr.Read())
{
draft.Add(new TestClass()
{
UserId = sdr.GetString(0),
Name = sdr.GetString(1),
Mobile = sdr.GetString(2),
Age = (sdr.GetValue(3) != DBNull.Value) ? sdr.GetValue(3) : "Null",
Date = (sdr.GetValue(4) != DBNull.Value) ?sdr.GetValue(4) : "Null"
});
}

Answer 2

Hi @Reborn ,
According to your needs, I think you can change the Age and Date types in your TestClass class to string, and change the Age and Date types of the codebehind to string at the same time, and change the code to the following:

public IHttpActionResult GetAll()  
        {  
            List<TestClass> draft = new List<TestClass>();  
            string mainconn = ConfigurationManager.ConnectionStrings["myconn"].ConnectionString;  
            SqlConnection sqlconn = new SqlConnection(mainconn);  
            string sqlquery = "SELECT UserId, Name, Mobile, Age, Date FROM tblTest";  
            sqlconn.Open();  
            SqlCommand sqlcomm = new SqlCommand(sqlquery, sqlconn);  
            SqlDataReader sdr = sqlcomm.ExecuteReader();  
            while (sdr.Read())  
            {  
                draft.Add(new TestClass()  
                {  
                    UserId = sdr.GetString(0),  
                    Name = sdr.GetString(1),  
                    Mobile = sdr.GetString(2),  
                    Age = (sdr.GetValue(3) != DBNull.Value) ? Convert.ToString(sdr.GetValue(3)) :"null",  
                    Date = (sdr.GetValue(4) != DBNull.Value) ? Convert.ToString(sdr.GetValue(4)) :"null"  
                });   
            }  
            return Ok(draft);  
        }  

Best regards,
Lan Huang

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