oracle extractvalue连接另一个表中标记名的值

我有一个奇怪的场景，我有两个表，其中包含以下类型的数据

table1: 
key1, xmldata1


    1,<start><dat1>hi/dat1><dat2>hello</dat2>........</end>
    2,<start><dat1>hihi/dat1><dat2>hellohello</dat2>.......</end>

table2:
key1, fld1, name1

    1, dat1, message1
    2, dat1, message2
    2, dat2, message3

---

这可能吗？表1 xmldata1中的dat1、dat2、dat3标记是动态的，可以有“n”个dat标记。

是的，有可能

select T2.key1, T2.name1, xmlcast(T1.xmldata1.extract('/start/'||T2.fld1) as varchar2(4000)) as message
from table2 T2
    join table1 T1
        on T1.key1 = T2.key1
;

或

select T2.key1, T2.name1, xmlcast(T1.xmldata1.extract('/start/'||T2.fld1) as varchar2(4000)) as message
from table2 T2
    join table1 T1
        on T1.key1 = T2.key1
;

select T2.key1, T2.name1, extractvalue(T1.xmldata1, '/start/'||T2.fld1) as message
from table2 T2
    join table1 T1
        on T1.key1 = T2.key1
;