Remove whitespaces after number - PostgreSQL - postgresql

Question

Basically, I want to remove the whitespace that exists after numbers
Input:
medication_title
CLORIDRATO DE VENLAFAXINA 75 MG
VIIBRYD 40 MG
KTRIZ UNO 0.6 U/G
Ouput:
medication_title medication_title2
CLORIDRATO DE VENLAFAXINA 75 MG CLORIDRATO DE VENLAFAXINA 75MG
VIIBRYD 40 MG VIIBRYD 40MG
KTRIZ UNO 0.6 U/G KTRIZ UNO 0.6U/G
Ideas?

Answer 1

We can use a regex replacement here:
SELECT
medication_title,
REGEXP_REPLACE(medication_title,
'\y(\d+(?:\.\d+)?) ([^[:space:]]*G)\y',
'\1\2') AS medication_title2
FROM yourTable;
Demo
Here is an explanation of the regex pattern:
\y word boundary
( match and capture in \1
\d+ a number
(?:\.\d+)? followed by optional decimal component
) close capture group \1
match a space (the one we want to remove)
( match and capture in \2
[^[:space:]]* zero or more leading non whitespace characters
G folllwed by "G"
) close capture group \2
\y another word boundary

Answer 2

You can capture the sequences with a regular expression and then assemble them back as needed, as in regexp_replace(x, '([^0-9]*[0-9]) +([^0-9\.]+)', '\1\2').
For example:
select *, regexp_replace(x, '([^0-9]*[0-9]) +([^0-9\.]+)', '\1\2') as y
from (
select 'CLORIDRATO DE VENLAFAXINA 75 MG'
union all select 'VIIBRYD 40 MG'
union all select 'KTRIZ UNO 0.6 U/G '
) t (x)
Result:
x y
-------------------------------- ------------------------------
CLORIDRATO DE VENLAFAXINA 75 MG CLORIDRATO DE VENLAFAXINA 75MG
VIIBRYD 40 MG VIIBRYD 40MG
KTRIZ UNO 0.6 U/G KTRIZ UNO 0.6U/G