how to determine the number of instances of a character in string in Oracle

I want to determine how many of a certain letter in a string, e.g., MTWRF10,TR34,TBD

these are class periods, so M=Mon, T=Tues, R=Thurs, etc.

I want to determine how many M's, for example. I can't figure out how to do this in Sql, plus PL/SQL is probably better, no ?

I guess it would just be walking character by character and counting up, I suppose. The logic processes a day at a time, so as I process Monday, I would just walk through the string and count my M's (while ignoring TBD, etc.).

So if there is a Sql trick, please advise. If not, and you have a code snippet to address, that would be excellent.

(oracle is such a broad term, but that looks like the only topic that applies, I don't see PL/SQL).

(I also don't see where to assign points anymore . . . is everything now 500 points ???)
Gadsden ConsultingIT SpecialistAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

slightwv (䄆 Netminder) Commented:
Single character?

length(string) - length(replace(string,'M'))
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Gadsden ConsultingIT SpecialistAuthor Commented:
yes, single character.

very slick ! (I should have thought of that . . . )
0
Gadsden ConsultingIT SpecialistAuthor Commented:
just what the patient needed !

Thx.
0
The Ultimate Tool Kit for Technolgy Solution Provi

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy for valuable how-to assets including sample agreements, checklists, flowcharts, and more!

slightwv (䄆 Netminder) Commented:
Just thought of something.

You wanted to ignore TBD but what I posted will include the 'T' when looking for Tuesday.

Simple fix.  Just grab everything up to the first comma and do the length as above.

There are a few ways but try this:
regexp_substr('MTWRF10,TR34,TBD','[^,]+')

If you are dealing with a LOT of data this one might be faster:
substr(:'MTWRF10,TR34,TBD',1,instr(:'MTWRF10,TR34,TBD',',')-1)
0
slightwv (䄆 Netminder) Commented:
>>(I also don't see where to assign points anymore . . . is everything now 500 points ???)

Looks like I even missed that change.  I was just informed that everything is now 500 points.
0
Gadsden ConsultingIT SpecialistAuthor Commented:
thanks - I used replace TBD with ''

regexp_substr looks good but I don't understand what is going on there . . .

same with the substr / instr . . . not sure there.

I will try both out tomorrow.

yeah on the 500 points - grade inflation !
0
slightwv (䄆 Netminder) Commented:
The magic is [^,]+

This looks for 1 or more characters '+'  that is NOT '^'  in this list '[]' of characters.  In this case only one, a comma ','


>>same with the substr / instr . . . not sure there.

instr returns the position of the first comma.  Then I subtract one position to remove the comma (really unnecessary for the regex), then grabs the substring from position 1 to that number.

>>grade inflation !

Changes at corporate.
0
Gadsden ConsultingIT SpecialistAuthor Commented:
ok, thanks for the expln . . . I'll try tomorrow.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Oracle Database

From novice to tech pro — start learning today.