How to add leading zeros into existing Column?

Question

I have one column ( zip varchar(10) ) in MySQL.
I am giving some value examples of this columns.

1. 576
2. 5768
3. 57689

I want to replace all three digits with adding 00 as prefix, all four digits with adding 0 prefix.
So after doing this operation my values should be,

1. 00576
2. 05768
3. 57689

Is it possible with any MySQL query? Any ideas?

Answer 1

The following query uses the LPAD function suggested by georstef.

UPDATE <tablename>
SET zip = LPAD(zip,5,'0');

Answer 2

You could use a stored procedure for this, inside your procedure check if CHAR_LENGTH() == 3 (you could use a variable instead of hardwiring 3 here)than use an if statement to set number of leading zeros to a variable. Than you could update the column with a concat function with the variable that has the leading zeros.