Question

I have a single table for which I wish to find all the instances where 0 is the last character in a string field. I tried this by using two methods and they each returned different results.

This first query seemed to actually return the correct answer

select * from icd
    where CHARINDEX('0',icd,LEN(icd)) =LEN(icd) 

this one does not catch all of the answers

select * from icd
    where PATINDEX('%0%',icd) = LEN(icd)

using

select t.ICD as theCharIndex,x.ICD as thePatIndex from
(

select * from icd
    where CHARINDEX('0',icd,LEN(icd)) =LEN(icd) 
) t
left join
(
select * from icd
    where PATINDEX('%0%',icd) = LEN(icd)
) x on x.ICD=t.ICD
where x.ICD is null

I found the set of data that CHARINDEX picked up that PATINDEX did not. I even did

update icd
set ICD=RTRIM(icd)

Why would PATINDEX indiscriminately leave out some rows?

Answer 1

Because you have a 0 somewhere before the end.
Change PATINDEX('%0%',icd) to PATINDEX('%0',icd)