Check only ALPHANUMERIC characters

karthi_gana · Post by **karthi_gana** » Wed Sep 30, 2015 2:56 am

All,

I have to check whether a string contains only alpha numeric characters.

I used ALPHA() Function, but it is not giving the expected result set.

Input file has
"STREAM GSDW NSC D" - Expected Result Set is OK

"STREAM GSDW1 NSC D" - Expected Result Set is FAILED.

As It contains "1".

ALPHA() or ISVALID(String,DSLInk1.columnname) functions are not returning the expected result set.

Note: The data type of the column is varchar(50)

Inputs are welcome!

rkashyap · Post by **rkashyap** » Wed Sep 30, 2015 5:44 am

"Alpha" function checks if the given string contains only alphabetic characters. In order to check for alphanumeric characters, use AlNum function.

qt_ky · Post by **qt_ky** » Wed Sep 30, 2015 6:06 am

It's been a while but I think those functions are strict in that if the string contains whitespace then they will return false. Is that correct? Spaces are not alphabetic nor numeric.

rkashyap · Post by **rkashyap** » Wed Sep 30, 2015 6:19 am

I believe that AlNum can handle spaces. Excerpt from example for AlNum function.

Examples. If mylink.mystring1 contains the string "OED_75_9*E", then the following function would return the value 0 (false).
AlNum(mylink.mystring1)

If mylink.mystring2 contains the string "12 red roses", then the following function would return the value 1 (true).
AlNum(mylink.mystring2)

qt_ky · Post by **qt_ky** » Wed Sep 30, 2015 10:39 am

Do not trust the documentation.

A quick test is in order. Here are a few input strings and function results from version 11.3.1.2.

Code: Select all

AlNum:1 Alpha:1 STRING:Alpha
AlNum:0 Alpha:0 STRING:Alpha with spaces
AlNum:0 Alpha:0 STRING:Alpha_with_underscores
AlNum:1 Alpha:0 STRING:AlphaNumeric123
AlNum:0 Alpha:0 STRING:Alpha Numeric 123 with spaces
AlNum:0 Alpha:0 STRING:Alpha_Numeric_123_with_underscores
AlNum:1 Alpha:0 STRING:123
AlNum:0 Alpha:0 STRING:1 2 3
AlNum:0 Alpha:0 STRING:1_2_3

To answer the original question/expectation, you would first have to remove whitespace then test using Alpha() or AlNum() depending on the desired results.

eostic · Post by **eostic** » Wed Sep 30, 2015 10:54 am

Nice test grid! This post ought to be a sticky. THANKS! ; )

chulett · Post by **chulett** » Wed Sep 30, 2015 11:41 am

You can always save it as a Favorite.

eostic · Post by **eostic** » Wed Sep 30, 2015 2:38 pm

Sounds like a good idea.....how does it work? Never used it. I see the "Favorites" link at the top, but don't see how to target a particular post.

Ernie

chulett · Post by **chulett** » Wed Sep 30, 2015 2:59 pm

The option to Add to Favorites is on the far right-hand side of the page, both at the very top and bottom of the page/screen. Clicking it will put a link to the topic in your Favorites so you can get back to it easily.

eostic · Post by **eostic** » Wed Sep 30, 2015 8:11 pm

Cool. Thanks. Never noticed it.

karthi_gana · Post by **karthi_gana** » Thu Oct 01, 2015 4:05 am

I removed the whitespaces by using stripwhitespace function and then applied ALPHA..But the output of ALPHA is 0 instaed of 1. why?

"STREAM GSDW nsc D"

I used the above string only in my file.

qt_ky · Post by **qt_ky** » Thu Oct 01, 2015 6:22 am

If you did a derivation like Alpha(StripWhiteSpace(Col)) and Col=a b c then it should return 1 for true. If the double quotes are actually part of the string as in Col="a b c" the it should return 0 for false. Check the quote character value you have set when reading the file.