change the first character in a field

Question

I wish to change the first character from a 'U' to an 'S' in a field in my table (MYSQL) , so far I have the following :

UPDATE customers_basket 
SET products_id = REPLACE(
                   LEFT(products_id,1), 'U', 'S') +      
                   SUBSTRING(products_id, 2, CHAR_LENGTH(products_id)
);

but this does not give me the desired effect, can any one help me?

thank you!

Answer 1

UPDATE customers_basket 
SET products_id = CONCAT(
                   REPLACE(
                      LEFT(products_id,1), 'U', 'S'),      
                      SUBSTRING(products_id, 2, CHAR_LENGTH(products_id)
));

You are trying to add characters together, e.g.

select 'c' + 'a';
+-----------+
| 'c' + 'a' |
+-----------+
|         0 |
+-----------+

Answer 2

update customers_basket 
set products_id = 'S' + SUBSTRING(products_id,2,CHAR_LENGTH(products_id))
where LEFT(products_id,1) = 'U'