oracle how to transpose columns into rows without UNION

问题

Assume, i have 4 columns in a table

id | col1 | col2 | col3 

now i want to transpose that into one column but in 4 rows:

result
-------
someid
col1data
col2data
col3data

How can i achieve that? Thanks!

回答1:

This can be done using unpivot.

select result 
from tablename
unpivot (result for colnames in (id,col1,col2,col3))

来源：https://stackoverflow.com/questions/39450776/oracle-how-to-transpose-columns-into-rows-without-union