从逗号分隔值加入原始表中获取表中的最新数据

Question

我创建了脚本以获取逗号分隔值，该值（cloumn1）与另一个表（column2）连接，（column1）具有n个重复我想从column1获取最新的前1并与column2连接。脚本 - ＆gt;

SELECT A.EmailHistoryid,
    Split.a.value('.', 'VARCHAR(100)') AS String,
    A.MailTo
INTO #tmp
FROM (
    SELECT EmailHistoryid,
        CAST('<M>' + REPLACE([requestinstanceids], ',', '</M><M>') + '</M>' AS XML) AS String,
        MailTo
    FROM [emailhistoryDT] NOLOCK
    ) AS A
CROSS APPLY String.nodes('/M') AS Split(a)
ORDER BY a.EmailHistoryid DESC;