How To Select All Columns of All Rows from a Table?

The simplest query statement is the one that selects all columns of all rows from a table:
"SELECT * FROM table_name;". The (*) in the SELECT clause tells the query to return all
columns. The tutorial exercise below gives you a good example:
SQL> SELECT * FROM departments;
DEPARTMENT_ID DEPARTMENT_NAME MANAGER_ID LOCATION_ID
------------- ------------------------------ ---------- -----------
10 Administration 200 1700
20 Marketing 201 1800
30 Purchasing 114 1700
40 Human Resources 203 2400
50 Shipping 121 1500
60 IT 103 1400
70 Public Relations 204 2700
80 Sales 145 2500
90 Executive 100 1700