How can I switch case for each letter in a string with SQL?

Question

I need to convert this into this using PostgreSQL

dxItw9a4 --> DXiTW9A4

Is there any function or way that is already set?

Answer 1

If you're only dealing with the characters A-Z, you can use the translate function in postgres to convert cases.

select TRANSLATE(
    'dxItw9a4', -- original text
    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz', -characters to change
    'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' -- replacement characters.
)

You can simplify it slightly be using the upper/lower functions.

select TRANSLATE(
    'dxItw9a4',  -- original text
    upper('dxItw9a4')||lower('dxItw9a4'), --characters to search for
    lower('dxItw9a4')||upper('dxItw9a4') -- replacement characters
);