Extract month and year from a date column (use stringfy before)
Regex with the string:
[0-9]{4}-[0-9]{2}
Extract the month from a timestamp formatted as "31071991"
(?<=\d{2})\d{2}
The expression in brackets is the expression which stands before the desired expression but which shall not be taken.
Search for empty values using Regex
'^$'
UTF-8 cheat sheet (can be used for example to convert malformed strings back to "ä", "ö", "ü" in the Regex processor)
https://bueltge.de/wp-content/download/wk/utf-8_kodierungen.pdf