Oracle: col formatting Method

COL command:
It mainly formats the display of columns.
This command has the following options:
COL [UMN] [{column | expr} [option...]
The Option can be the following clause:
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ALI [AS] alias
CLE [AR]
FOLD_A [FTER]
FOLD_ B [EFORE]
FOR [MAT] format
HEA [DING] text
JUS [cipher] {L [EFT] | C [ENTER] | C [ENTRE] | R [IGHT]}
LIKE {expr | alias}
NEWL [INE]
NEW_V [ALUE] variable
NOPRI [NT] | PRI [NT]
NUL [L] text
OLD_V [ALUE] variable
ON | OFF
WRA [PPED] | WOR [D_WRAPPED] | TRU [NCATED]

1). Change the default Column Title
COLUMN column_name HEADING column_heading -- The experiment failed to change the title command. I don't know what the problem is.
For example:
SQL> select * from dept;
DEPTNO DNAME LOC
-----------------------------------------------
10 ACCOUNTING NEW YORK
SQL> col LOC heading location
SQL> select * from dept;
Deptno dname location
------------------------------------------------
10 ACCOUNTING NEW YORK

2) Change the column NAME to the new column NAME "employee name" and put the new column NAME on two rows:
SQL> select * from emp
Department name Salary
------------------------------
10 aaa 11
SQL> COLUMN ENAME HEADING 'employee | name'
SQL> select * from emp
Employee
Department name Salary
------------------------------
10 aaa 11
Note: the col heading turn into two lines from one line.

3). Change the display length of the column:
FOR [MAT] format
SQL> select empno, ename, job from emp;
EMPNO ENAME JOB
-----------------------------
7369 SMITH CLERK
7499 ALLEN SALESMAN
7521 WARD SALESMAN
SQL> col ename format a40
EMPNO ENAME JOB
-----------------------------------------------------------
7369 SMITH CLERK
7499 ALLEN SALESMAN
7521 WARD SALESMAN

4). Set the column title alignment
JUS [cipher] {L [EFT] | C [ENTER] | C [ENTRE] | R [IGHT]}
SQL> col ename justify center
SQL>/
EMPNO ENAME JOB
-----------------------------------------------------------
7369 SMITH CLERK
7499 ALLEN SALESMAN
7521 WARD SALESMAN
For NUMBER-type columns, the column title is on the right by default, and for other types of columns, the column title is on the left by default.
5). prevent a column from being displayed on the screen.
NOPRI [NT] | PRI [NT]
SQL> col job noprint
SQL>/
EMPNO ENAME
--------------------------------------------------
7369 SMITH
7499 ALLEN
7521 WARD

6). format the display of NUMBER columns:
SQL> COLUMN SAL FORMAT $99,990
SQL>/
Employee
Department Name Salary Commission
---------------------------------------
30 ALLEN $1,600 300

7). If the column value is NULL when the column value is displayed, replace the NULL value with the text value.
Comm nul [L] text
SQL> COL COMM NUL [L] text

8). Set the rewinding Method for a column.
WRA [PPED] | WOR [D_WRAPPED] | TRU [NCATED]
COL1
--------------------
How are you?

SQL> COL COL1 FORMAT A5
SQL> COL COL1 WRAPPED
COL1
-----
HOW
RE YO
U?

SQL> COL COL1 WORD_WRAPPED
COL1
-----
HOW
ARE
YOU?

SQL> COL COL1 WORD_WRAPPED
COL1
-----
HOW
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9). display the current display attribute value of the column
SQL> COLUMN column_name

10). Set the display attribute of all columns to the default value.
SQL> CLEAR COLUMNS