how use distinct in second join table in sql server - sql

Question

I have a SQL table consists of id, name, email,.... I have another SQL table that has id, email, emailstatus but these 2 id are different they are not related. The only thing that is common between these 2 tables are emails.
I would like to join these 2 tables bring all the info from table1 and if the email address from table 1 and table 2 are same and emailstatus is 'Bounced'. But the query that I am writing gives me more record than I expected because there are multiple rows in tbl_webhook(second table) for each row in Applicant(first table) .I want to know if applicant has EVER had an email bounce.
Query without join shows 23000 record but after join shows 42000 record that is because of duplicate how I can keep same 23000 record only add info from second table?
This is my query:
SELECT
A.[Id]
,A.[Application]
,A.[Loan]
,A.[Firstname]
,A.[Lastname]
,A.[Email],
,H.[Email], H.[EmailStatus] as BouncedEmail
FROM Applicant A (NOLOCK)
left outer join [tbl_Webhook] [H] (NOLOCK)
on A.Email = H.Email
and H.[event]='bounced'
this is sample of desired data:
id email name emailFromTable2 emailstatus
1 test2#yahoo.com lili test2#yahoo.com bounced
2 tesere#yahoo.com mike Null Null
3 tedfd2#yahoo.com nik tedfd2#yahoo.com bounced
4 tdfdft2#yahoo.com sam Null Null
5 tedft2#yahoo.com james tedft2#yahoo.com bounced
6 tedft2#yahoo.com San Null

Answer 1

Use a nested select for this type of query. I would write this as:
select id, application, load, firstname, lastname, email,
(case when BouncedEmail is not null then email end) as EmailFromTable2,
BouncedEmail
from (SELECT A.[Id], A.[Application], A.[Loan], A.[Firstname], A.[Lastname], A.[Email],
(case when exists (select 1
from tbl_WebHook h
where A.Email = H.Email and H.[event] = 'bounced'
)
then 'bounced
end) as BouncedEmail
FROM Applicant A (NOLOCK)
) a
You can also do this with cross apply, but because you only really need one column, a correlated subquery also works.

Answer 2

;WITH DistinctEmails
AS
(
SELECT * , rn = ROW_NUMBER() OVER (PARTITION BY [Email] ORDER BY [Email])
FROM [tbl_Webhook]
)
SELECT
A.[Id]
,A.[Application]
,A.[Loan]
,A.[Firstname]
,A.[Lastname]
,A.[Email],
,H.[Email], H.[EmailStatus] as BouncedEmail
FROM Applicant A (NOLOCK) left outer join DistinctEmails [H] (NOLOCK)
on A.Email = H.Email
WHERE H.rn = 1
and H.[event]='bounced'

Answer 3

i believe query below should be enough to select distinct bounced email for you, cheer :)
SELECT
A.[Id]
,A.[Application]
,A.[Loan]
,A.[Firstname]
,A.[Lastname]
,A.[Email],
,H.[Email], H.[EmailStatus] as BouncedEmail
FROM Applicant A (NOLOCK)
Inner join [tbl_Webhook] [H] (NOLOCK)
on A.Email = H.Email
and H.[EmailStatus]='bounced'
basically i just change the joining to inner join and change the 2nd table condition from event to emailstatus, if u can provide your table structure and sample data i believe i can help you up :)