Eine Einführung in

SQL

To select the data from 20 different columns into one changing the values according to one other column consisting the positions of the 20 columns

Oracle
Sometimes we have un-normailsed data that we want to normalise. Suppose we have data in 20 columns F1 to F20:
Line    F1    F2   F3   F4 ...
------------------------------
A       11    10   13   15 ...
B       20    22   23   28 ...
But we want a table that has just one data column. Like this...
Line   Col   Val
----------------
A      1     11
A      2     10
A      3     13
A      4     15
...
B      1     20
B      2     22
B      3     23
B      4     28
...

You can use INSERT ... SELECT ... statement

Execute tidy up code silently
Execute set up code


Specific to Oracle
none