Join issue

Question

Post reply

Join issue

ehlinger

Hall of Fame

Points: 3585
More actions
April 25, 2008 at 9:26 am

#185782

I had one of our programmers come to me this morning and she is trying to update some information in one of our tables. They have the changes in an Excel spreadsheet and have imported it into a work table in SQL. The fields that they are trying to join on are identical. Both are char(14). (I realize that both of these fields should probably be an int but dealing with a legacy system.) However, the following query won't return any results:

SELECT *

FROM dm_prod dm_p JOIN wk_BricsCad w ON dm_p.SsProdid = w.SsProdid

If I open the work table and edit the the ssprodid field and manually delete the extra spaces at the end of the field out and then run the query I get one match.

So, logically, I figured why not run an update to the work table and trim the ssprodid field. That should get the query to match on all 700+ records. Still only one match.

Any ideas as to what is going on here?

Viewing 7 posts - 1 through 6 (of 6 total)

You must be logged in to reply to this topic. Login to reply

Jack Corbett SSC Guru Points: 184388 More actions · Answer 1

Running:



Update table

     Set char_field = Rtrim(char_field)

Does not actually trim as the char data type is fixed width so the data is right padded with spaces. Now changing the data type to varchar(14) and then running the RTRIM will remove spaces on the end.

You could do this in your join:



Select

From

      tableA A Join

      tableB B On

             RTrim(A.char_field) = RTrim(B.char_field)

Of course this is likely to cause a table scan.

Jack Corbett
Consultant - Straight Path Solutions
Check out these links on how to get faster and more accurate answers:
Forum Etiquette: How to post data/code on a forum to get the best help
Need an Answer? Actually, No ... You Need a Question

RyanRandall SSChampion Points: 13623 More actions · Answer 2

The characters are probably some other 'invisible' characters - like tabs or returns.

Use something like this to figure out what the ascii values are...

select distinct ascii(substring(MyColumn, number, 1)) from myTable cross join

(select distinct number from master.dbo.spt_values where number between 0 and 14) a

Use something like this to update them (this could be faster but it will do the job). Alternatively you can hard-code the replaces based on the results of the previous query.

select 0 --to set @@rowcount