I need some help plz some one replay me

Question

i wont to write a query to have result like this table from emp table
length_for length_fif length_sex
KING BLAKE MARTIN
WARD CLARK TURNER
FORD JONES MILLER
ALLEN
JAMES
SMITH
SCOTT
ADAMS
this is what i can do
but it's not work
select decode(length(ename),4,ename) for_lnth,
decode(length(ename),5,ename) fif_lnth,
decode(length(ename),6,ename) sex_lnth
from emp;
FOR_LNTH FIF_LNTH SEX_LNTH
KING
BLAKE
CLARK
JONES
MARTIN
ALLEN
TURNER
JAMES
WARD
FORD
SMITH
SCOTT
ADAMS
MILLER
there's many field Null and i don't wont to write the number of letter like 4,5,6 in the query
i wont the query find out how many letter are there in the name
and aaaaaaaaaaaaa
i'm waiting.....

Answer 1

Hi,
Welcome to the forum!
This site replaces multiple whitespace with a single space by default, so things that are nicely formatted when you post them look terrible after you post them.
Type these 6 characters
{code}
(small letters only, inside curly brackets) before and after formatted text, to preserve spacing.
Re-arranging your one-column output into three columns is called pivoting.
Here's one way to do it:
WITH     got_rnum
AS
     SELECT     ename
     ,     LENGTH (ename)     AS len
     ,     ROW_NUMBER () OVER ( PARTITION BY  LENGTH (ename)
                               ORDER BY          ename     -- optional
                       )  AS rnum
     FROM     scott.emp
SELECT       MAX (CASE WHEN len = 4 THEN ename END)     AS length_4
,       MAX (CASE WHEN len = 5 THEN ename END)     AS length_5
,       MAX (CASE WHEN len = 6 THEN ename END)     AS length_6
FROM       got_rnum
GROUP BY  rnum
ORDER BY  rnum;The only place where I had to know what the lengths were was when I wrote three lines for the SELECT clause (for lengths 4, 5, and 6).
If you the query to do this, then you have to use dynamic SQL, to figure out how many different lengts there are, and what they are, and to write an appropriate SELECT clause for you.
As dynamic SQL gioes, this is pretty easy. You can do it in SQL*Plus or PL/SQL.