asked on

SQL help needed

Hi Experts

I have a rather complicated stored proc that does take a few seconds to run, it loads customer data from several sources into a temp table, and returns that table.

What I need now is a way to mark customers that have the same name but different ID's so the users can perform additional checks to make sure they have the right one.

I can't think of an efficient way to do this. Maybe a count on name in the temp table?

Andy

Phillip Burton

Use the HAVING clause.

Phillip Burton

Here's my code:

drop table Customers
go

create table Customers
(ID int,
Name varchar(50),
Warning bit null)
go

insert into Customers(ID, Name)
values (1, 'FirstName'), (2, 'SecondName'), (3, 'ThirdName'), (4, 'FirstName')
go

update Customers
set Warning = 0
from Customers
go

with RowsToUpdate as
(select Name, Warning
From Customers
group by Name, Warning
having Count(ID)>1)

update Customers
set Warning = 1
from Customers 
inner join RowsToUpdate 
on Customers.Name = RowsToUpdate.Name

select * from Customers

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PortletPaul

Not sure what the field is that you are evaluating, but assuming it's [CUSTOMER_ID] then you would want DISTINCT in the evaluation I think. e.g.

HAVING COUNT(DISTINCT [CUSTOMER_ID]) > 1

e.g.

select *
from staging 
where customer in (
          select Customer
          from staging
          group by Customer
          HAVING COUNT(DISTINCT [CUSTOMER_ID]) > 1
          )

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Andy Green

ASKER

Its just customer name, its to identify the same name but different ID.

Trying your solution Phillip. Thanks

Andy

Andy Green

ASKER

Phillip I'm using a table variable for my temp table, and The sample you supplied works fine as you have it but not with a table variable,

Declare @Customers table
(ID int,
Name varchar(50),
Warning bit null)

Andy

Andy Green

ASKER

ALso Its not a limited list I need rather as Phillip has done it all the rows with a flag if the name exists in another record.

Andy

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Phillip Burton

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Andy Green

ASKER

I did but it looks like you have to alias the table as you have done.

Andy

Andy Green

ASKER

Nearly there, just struggling on one last point, It is possible that the same Customer could appear in the list 2 or 3 times, I don't want these highlighted, just those with different ID'd but the same names.

This is in Wales where same names can be common.

Andy

Phillip Burton

Change the line

having Count(ID)>1)

to

having Count(DISTINCT ID)>1)

Andy Green

ASKER

Sorry still not right:

In this an expanded version of your original code I don't want 4 FirstName to have a warning:

declare @Customers as table
(ID int,
Name varchar(50),
Warning bit null)

insert into @Customers(ID, Name)
values (1, 'FirstName'), (2, 'SecondName'), (3, 'ThirdName'), (4, 'FirstName'), (1, 'FirstName')

update @Customers
set Warning = 0
from @Customers;

with RowsToUpdate as
(select Name, Warning
From @Customers
group by Name, Warning
having Count(Distinct ID)>1)

update @Customers
set Warning = 1
from @Customers C
inner join RowsToUpdate R
on C.Name = R.Name

select * from @Customers

Andy Green

ASKER

Hang on ignore that - I'm getting confused now.

Andy

Andy Green

ASKER

Sorry Phillip, you are right. Worked fine with Distinct.

Andy

Andy Green

ASKER

Excellent - Thank you.

Andy

Phillip Burton

You may perhaps want to change the very final line to

select distinct * from @Customers