C#过滤DataTable中空数据和重复数据的示例代码

string sql = "select name,age from user";
DataTable data = DB.ExecuteDataTable(string.Format(sql)); //得到DataTable

// ------------start 去重-------------------
string[] distinctcols = new string[(data.Columns.Count)];
foreach (DataColumn dc in data.Columns)
{
 distinctcols[dc.Ordinal] = dc.ColumnName;
}
DataView mydataview = new DataView(data);
DataTable data1 = mydataview.ToTable(true, distinctcols);
// ------------end  -------------------

// ------------start 去null-------------------
DataTable data2 = data1.Clone();//克隆表
foreach (DataRow drItem in data1.Rows)
{
	//过滤，判断条件的下标自己控制
 if (!string.IsNullOrWhiteSpace(drItem[0].ToString()) && !string.IsNullOrWhiteSpace(drItem[1].ToString()))
 {
  data2.Rows.Add(drItem.ItemArray);
 }
}
// ------------end-------------------

/**
下面没啥用，增加一行空白行，搜索的时候当全部搜索用
*/
DataRow row = data2.NewRow();
data2.Rows.InsertAt(row, 0);
return data2;

if(!DataRow.IsNull(index))

if(Convert.IsDBNull(Row.ItemArray[index]))

public static DataTable TblFilter(DataTable sourceTable, string condition)
    {
      var tempDt = sourceTable.Clone();
      var rows = sourceTable.Select(condition);
      foreach (var dr in rows)
      {
        tempDt.ImportRow(dr);
      }
      return tempDt;
    }


    public static DataTable TblFilter(DataTable sourceTable, string condition, string[] columns)
    {
      var tempDt = new DataTable();
      foreach (var t in columns)
      {
        tempDt.Columns.Add(t, typeof(String));
      }
      var rows = sourceTable.Select(condition);
      foreach (var dr in rows)
      {
        var newDr = tempDt.NewRow();
        foreach (var t in columns)
        {
          newDr[t.Split(':')[0]] = dr[t.Split(':')[0]].ToString();
        }
        tempDt.Rows.Add(newDr);
      }
      return tempDt;
    }

LEFT(shopid,4)