Update Table with Join NOT RBAR

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Update Table with Join NOT RBAR

nfs_john

Ten Centuries

Points: 1275
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October 30, 2012 at 1:14 pm

#264816

Hello,
My problem today is that when this company started they had no standards for data entry. So one person could enter Alabama and another Al while a third AL. I have identified 12 tables with a state column and these tables may have records of this nature. We now have a standard for entering states as the two letter abbreviation. So my task is to find situations such as Alabama and update it to AL.
I know I don't want to do this RBAR so I was thinking of doing it with a Join but I'm not sure how to update with a join. Would my control table have two colums? Column A would be the incorrect way and column B would be the correct way? We would use column A to join on and column B to update to the correct value?
What about situations that I can't think ahead to match such as a typo where Alabamma does not match anything. Is there a way to have one entry in the control join table that is a wildcard and append a GOOFY_ so that I can then query for GOOFY and zap the odd balls?
Thnaks for pointing me in the right direction
JB

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Sean Lange SSC Guru Points: 286590 More actions · Answer 1

nfs_john (10/30/2012)
Hello,
My problem today is that when this company started they had no standards for data entry. So one person could enter Alabama and another Al while a third AL. I have identified 12 tables with a state column and these tables may have records of this nature. We now have a standard for entering states as the two letter abbreviation. So my task is to find situations such as Alabama and update it to AL.
I know I don't want to do this RBAR so I was thinking of doing it with a Join but I'm not sure how to update with a join. Would my control table have two colums? Column A would be the incorrect way and column B would be the correct way? We would use column A to join on and column B to update to the correct value?
What about situations that I can't think ahead to match such as a typo where Alabamma does not match anything. Is there a way to have one entry in the control join table that is a wildcard and append a GOOFY_ so that I can then query for GOOFY and zap the odd balls?
Thnaks for pointing me in the right direction
JB

Kudos for realizing that RBAR is not the best approach here. I tossed together an example of how you could do this. It would be far easier if we had your ddl to work with but this should show at least one way to do it.

create table #BadData

(

BadState varchar(25),

ST char(2)

)

insert #BadData

select 'Alabama', null union all

select 'AL', null union all

select 'Alabadma', null

create table #StateLookup

(

ST char(2),

StateName varchar(50)

)

insert #StateLookup

select 'AK', 'Alaska' union all

select 'AL', 'Alabama' union all

select 'AR', 'Arkansas' union all

select 'AZ', 'Arizona' union all

select 'CA', 'California' union all

select 'CO', 'Colorado' union all

select 'CT', 'Connecticut' union all

select 'DC', 'District Of Columbia' union all

select 'DE', 'Delaware' union all

select 'FL', 'Florida' union all

select 'GA', 'Georgia' union all

select 'HI', 'Hawaii' union all

select 'IA', 'Iowa' union all

select 'ID', 'Idaho' union all

select 'IL', 'Illinois' union all

select 'IN', 'Indiana' union all

select 'KS', 'Kansas' union all

select 'KY', 'Kentucky' union all

select 'LA', 'Louisiana' union all

select 'MA', 'Massachusetts' union all

select 'MD', 'Maryland' union all

select 'ME', 'Maine' union all

select 'MI', 'Michigan' union all

select 'MN', 'Minnesota' union all

select 'MO', 'Missouri' union all

select 'MS', 'Mississippi' union all

select 'MT', 'Montana' union all

select 'NC', 'North Carolina' union all

select 'ND', 'North Dakota' union all

select 'NE', 'Nebraska' union all

select 'NH', 'New Hampshire' union all

select 'NJ', 'New Jersey' union all

select 'NM', 'New Mexico' union all

select 'NV', 'Nevada' union all

select 'NY', 'New York' union all

select 'OH', 'Ohio' union all

select 'OK', 'Oklahoma' union all

select 'OR', 'Oregon' union all

select 'PA', 'Pennsylvania' union all

select 'RI', 'Rhode Island' union all

select 'SC', 'South Carolina' union all

select 'SD', 'South Dakota' union all

select 'TN', 'Tennessee' union all

select 'TX', 'Texas' union all

select 'UT', 'Utah' union all

select 'VA', 'Virginia' union all

select 'VT', 'Vermont' union all

select 'WA', 'Washington' union all

select 'WI', 'Wisconsin' union all

select 'WV', 'West Virginia' union all

select 'WY', 'Wyoming'

select *

from #BadData bd

left join #StateLookup sl on sl.ST = bd.BadState or sl.StateName = bd.BadState

update #BadData

set ST = sl.ST

from #BadData bd

left join #StateLookup sl on sl.ST = bd.BadState or sl.StateName = bd.BadState

--But what about the ones that didn't find a match???

select * from #BadData where ST is null

drop table #BadData

drop table #StateLookup

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nfs_john Ten Centuries Points: 1275 More actions · Answer 2

Mr. Lange,

Sorry for the delay I was pulled off to another fire before coming back to this project. As for this question and answer I don't see where to mark as an answer or give you credit but your post provided enough to jog my memory back into RDBM & TSQL world. I created my update tables and executed the joins. It all worked quite nicely.

THANK YOU

JB

Sean Lange SSC Guru Points: 286590 More actions · Answer 3

nfs_john (11/26/2012)
Mr. Lange,
Sorry for the delay I was pulled off to another fire before coming back to this project. As for this question and answer I don't see where to mark as an answer or give you credit but your post provided enough to jog my memory back into RDBM & TSQL world. I created my update tables and executed the joins. It all worked quite nicely.
THANK YOU
JB

Glad that worked for you. Around here we don't have a mechanism for "Mark as Answer" or that type of thing. All threads remain open because there may be somebody else who comes along and has a different approach to the same issue that is better than the posted "answer". As far as credit...well you just gave it to me by your comment. Thanks for letting me know that worked and as always feel free to post here or start a new thread when you find yourself in need of help in the future.

_______________________________________________________________

Need help? Help us help you.

Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/