datatable 某一列转字符串，和字符串去重

datatable 某一列转字符串

https://www.cnblogs.com/yyxhgy/p/9814934.html

https://www.cnblogs.com/zhaogaojian/p/10527212.html

  string[] mid= dt.Rows.OfType<DataRow>().Select(r => r["MID"].ToString()).ToArray();
           string mids= String.Join(",", mid);

list 转字符串也差不多，

String.Join(",", list.Select(c => c.MID).ToArray());

我使用的datatable 获取一列是有重复的，使用了mid = mid.Distinct().ToArray(); 数组去重

另外记录一下字符串去重

string.Join(",", str.Split(',').Distinct().ToArray());

正则的没看

 string ddd= (from d in DataTable select d.Field<string>("collectionMoldDate")).Last();//获取最后一行的的指定列值