SQL join to identify group members - sql

Question

I have got a client table which pretty much looks like below:
Client List
customer no. Customer name
123 Kristen Smith
128 Jeremy Church
127 Alan Li
132 Ryan Nelson
I need to map it to a Customer_Dim table
Customer_Dim
customer no. Customer name Group no. Group Name Cust_Active Flag
123 Kristen Smith 5491 Zealong Tea Estate Y
167 Anna Hathaway 5823 AA Insurance Y
146 Simon Joe 5671 Direct Automobile Y
148 Henry Wilson 5823 AA Insurance Y
195 Graham Brown 5491 Zealong Tea Estate Y
172 Daria Smith 5671 Direct Automobile N
122 Dyana Smith 5823 AA Insurance N
132 Ryan Nelson 5671 Direct Automobile N
128 Jeremy Church 5823 AA Insurance Y
127 Alan Li 5671 Direct Automobile Y
to get their group numbers from below table (which I am able to do by a simple left join)
to list all the remaining customers (who are active) from the group numbers of the client customer [I AM UNABLE TO DO THIS 2nd PART] :
Required Results :
Customer No. Customer name Group No. Group Name
123 Kristen Smith 5491 Zealong Tea Estate
128 Jeremy Church 5823 AA Insurance
127 Alan Li 5671 Direct Automobile
195 Graham Brown 5491 Zealong Tea Estate
167 Anna Hathaway 5823 AA Insurance
148 Henry Wilson 5823 AA Insurance
146 Simon Joe 5671 Direct Automobile
Please let me know if any other information is needed.
Sorry, if a similar question has been asked earlier - did several searches but was unable to find anything.
Thanks

Answer 1

join the tables to get all the group numbers of the clients in the client list and then select from customer_dim only the clients of these group numbers who are active:
select * from customer_dim
where
cust_active_flag = 'Y'
and
groupno in (
select groupno
from client_list l inner join customer_dim d
on d.customerno = l.customerno
)
See the demo.
Results:
> customerno | customername | groupno | groupname | cust_active_flag
> ---------: | :------------ | ------: | :----------------- | :---------------
> 123 | Kristen Smith | 5491 | Zealong Tea Estate | Y
> 167 | Anna Hathaway | 5823 | AA Insurance | Y
> 146 | Simon Joe | 5671 | Direct Automobile | Y
> 148 | Henry Wilson | 5823 | AA Insurance | Y
> 195 | Graham Brown | 5491 | Zealong Tea Estate | Y
> 128 | Jeremy Church | 5823 | AA Insurance | Y
> 127 | Alan Li | 5671 | Direct Automobile | Y

Answer 2

for get required results you need a condition in your join
SELECT *
FROM Client c
JOIN Customer_Dim cd on c.CustomerNo = cd.CustomerNo
and cd.Cust_ActiveFlag ='Y'
or
SELECT *
FROM Client c
JOIN Customer_Dim cd on c.CustomerNo = cd.CustomerNo
WHERE cd.Cust_ActiveFlag ='Y'

Answer 3

I think it is pretty simple to get your posted result from Customer_Dim table.
if you don't want Group No. of ClientList
select * from Customer_Dim
where [Cust_Active Flag] = 'Y'
and [Group No.] not in (
select CD.[Group No.] from [Client List] as CL inner join Customer_Dim as CD where CL.[customer no.] = CD.[customer no.] )
And
if you only want Group No. of ClientList
select * from Customer_Dim
where [Cust_Active Flag] = 'Y'
and [Group No.] in (
select CD.[Group No.] from [Client List] as CL inner join Customer_Dim as CD where CL.[customer no.] = CD.[customer no.] )

Answer 4

For the case of a client being inactive and wanting to identify the client in the result set you can do a LEFT JOIN with a GROUP BY and leverage Proc SQL automatic remerging in a HAVING clause for selection criteria.
data client_list; input
custno custname:& $30.; datalines;
123 Kristen Smith
128 Jeremy Church
127 Alan Li
132 Ryan Nelson
899 Julius Caesar
run;
data customer_dim; input
custno custname:& $30. groupnum groupname:& $30. Cust_Active_Flag: $1.; datalines;
123 Kristen Smith 5491 Zealong Tea Estate Y
167 Anna Hathaway 5823 AA Insurance Y
146 Simon Joe 5671 Direct Automobile Y
148 Henry Wilson 5823 AA Insurance Y
195 Graham Brown 5491 Zealong Tea Estate Y
172 Daria Smith 5671 Direct Automobile N
122 Dyana Smith 5823 AA Insurance N
132 Ryan Nelson 5671 Direct Automobile N
128 Jeremy Church 5823 AA Insurance Y
127 Alan Li 5671 Direct Automobile Y
231 Donald Duck 7434 Orange Insurance Y
899 Julius Caesar 4999 Emperors N
900 Joshua Norton 4999 Emperors N
925 Joaquin Guzman 4999 Emperors Y
925 Naruhito 4999 Emperors Y
run;
proc sql;
create table want(label="Active customers of clients groups") as
select
LIST.custno as client,
DIM.*
from
customer_dim DIM
left join
client_list LIST
on
DIM.custno = LIST.custno
group by
groupnum
having
N(LIST.custno) > 0
and
(
cust_active_flag = 'Y'
or LIST.custno is not NULL
)
order by
groupnum, custno
;