What is the major difference between Varchar2 and char

Question

Creating Table:

CREATE TABLE test (
charcol    CHAR(10),
varcharcol VARCHAR2(10));

SELECT LENGTH(charcol), LENGTH(varcharcol) FROM test;
         


        

Answer 1

Simple example to show the difference:

SELECT 
    '"'||CAST('abc' AS VARCHAR2(10))||'"', 
    '"'||CAST('abc' AS CHAR(10))||'"' 
FROM dual;


'"'||CAST('ABC'ASVARCHAR2(10))||'"' '"'||CAST('ABC'ASCHAR(10))||'"'
----------------------------------- -------------------------------
"abc"                               "abc       "                   
1 row selected.

The CHAR is usefull for expressions where the length of charaters is always fix, e.g. postal code for US states, for example CA, NY, FL, TX