构建emply列的c＃代码。

  public   static   string  show（ int  r）
 {
 if （r >   0 ）
 {
 List< string> list =  new  List< string>（）; 
 for （ int  i =  0 ; i <  r; i ++）
 {
 list.Add（ ''as emplty_column +（i +  1 ））; 
} 

 return   string  .Join（ ，，list）; 
} 
 return    跨度>; 
} 

  string  val = show（ 5 ）; 
 string  strquery = @   SELECT a。 str_typeid，a.str_typename，a.str_status，a.strlst_user，
 a.dt_entdate +（（val ==  ）？ ： ， + val）+ @   
 FROM ref_productitem_disc a; 

你的strQuery将是查询。

I have an integer variable called x. I want a select query with creating x number of empty columns. How can I write this ? I can't use loop because I have to use this query as a c# string in my application.

as an example I can create one empty column as below

SELECT a.str_typeid, a.str_typename, a.str_status, a.strlst_user,
       a.dt_entdate, '' as empty_column
  FROM ref_productitem_disc a

Then I want use x to number of empty columns. In other words , how can I create x number of empty columns?

Your c# code to construct the emply column.

public static string show(int r)
        {
            if (r > 0)
            {
                List<string> list = new List<string>();
                for (int i = 0; i < r; i++)
                {
                    list.Add("'' as emplty_column" + (i + 1));
                }

                return string.Join(",", list);
            }
            return "";
        }

string val = show(5);
            string strquery = @"SELECT a.str_typeid, a.str_typename, a.str_status, a.strlst_user,
       a.dt_entdate" + ((val == "") ? "" : ","+val) + @"
  FROM ref_productitem_disc a";

Your strQuery will the query.