I have a column that should contain phone numbers but it contains whatever the user wanted. I need to create an update to remove all the characters after an invalid character.
To do this I am using a regex as PATINDEX('%[^0-9+-/()" "]%', [MobilNr]) and it seemed to work until I had some numbers as +1235, 36446 and to my surprise the result is 0 instead of 6. Also if the number contains . it returns 0.
Does PATINDEX ignores dot(".") and comma(",")? Are there other characters that PATINDEX will ignore?
It's not that PATINDEX ignores the comma and the dot, it's your pattern that created this problem.
With PATINDEX, the hyphen char (-) has a special meaning - it's in fact an operator that denotes an inclusive range - like 0-9 denotes all digits between 0 and 9 - so when you do +-/ it means all the chars between + and / (inclusive, of course). The comma and dot chars are within this range, that's why you get this result.
Fixing the pattern is easy: either use | as a logical or, or simply move the hyphen to the end of the pattern:
SELECT PATINDEX('%[^0-9/()" "+-]%', '+1235, 36446') -- Result: 6