Teradata字符比较

Question

在C＃应用程序中，我从Teradata表中填充了DataTable。 teradata表数据如下所示：

UnitNum UnitName
------- --------
123456  Location A1 - 123456 
123456  Location B1 - 123456

我想创建如下所示的输出：

UnitNum UnitName
------- --------
123456  Location A1 / B1 - 123456

我已在C＃中使用以下代码完成此操作：

string compSql2 = "SELECT UnitNum , 
                   UPPER(MAX((CASE a.RNK WHEN 1 THEN a.UnitName ELSE NULL END))) Location1,
                   UPPER(MAX((CASE a.RNK WHEN 2 THEN a.UnitName ELSE NULL END))) Location2 
                   FROM (SELECT UnitNum , UnitName, RANK(UnitName) AS RNK 
                     FROM idw_app_field_sync.compressor_list GROUP BY UnitNum) AS a 
                   GROUP BY 1";
        DataTable compdt = TeradataConnector.RunQuery(compSql2);

        compdt.Columns.Add("UnitName");
        for (int i = 0; i < compdt.Rows.Count; i++)
        {
            if (compdt.Rows[i].Field<string>("Location2") != null)
            {
                string loc1 = compdt.Rows[i].Field<string>("Location1");
                string loc2 = compdt.Rows[i].Field<string>("Location2");
                string unitname;

                for (int j = 0; j < loc1.Length - 9; j++)
                {
                    if (!loc2[j].Equals(loc1[j]))
                    {
                        unitname = loc2.Substring(0, loc2.Length - 9) + @" / " + loc1.Substring(j);
                        compdt.Rows[i].SetField<string>("UnitName", unitname);
                    }
                }
            }
            else
            {
                compdt.Rows[i].SetField<string>("UnitName", compdt.Rows[i].Field<string>("Location1"));
            }
        }

如果可能的话，我想在Teradata SQL中完成此任务。但是，我不知道如何将字符串的字符与SQL进行比较，就像我使用C＃一样。