Struggling with IF statement SQL Beginner - tsql

Question

UPDATE dbo.Contact
SET emailMessenger = '63' WHERE personID = #personID
WHILE (SELECT Email FROM Contact WHERE personID = #personID) != #email
BEGIN
IF (SELECT Email FROM Contact WHERE personID = #personID) IS NULL
UPDATE Contact SET Email = #personID WHERE personID = #personID
ELSE IF (SELECT Email FROM Contact WHERE personID = #personID) IS NOT NULL
UPDATE Contact SET SecondaryEmail = email WHERE personID = #personID
UPDATE Contact SET email = #email WHERE personID = #personID
END
What i'm trying to do is add an employees work email to primaryemail. But if they already have a personal email, then I want to first move that to the secondaryemail. But only for the specified employee hence the PersonID.
I've looked at a lot of different examples using CASE and IF-THEN. I think i'm adding too much to the statement. I really thought this Stackoverflow queston would help. I know its going to be the syntax or how it's structured.

Answer 1

Could you can do it with an update avoding trigger
UPDATE dbo.Contact
SET emailMessenger = '63',
dbo.Contact,
SecondaryEmail = CASE when Email is not null then Email else SecondaryEmail end ,
Email = CASE when email is null then 'studentemail.com'
when email <>'studentemail.com' then 'studentemail.com' else email end
where personID = '18403';

Answer 2

If I'm following your logic correctly, the following should do the trick.
I first set up a testing table with all possible problem permutations (email present in one, both, or neither column). If your data doesn't look something like this, my solution may not apply.
drop table Contact
CREATE TABLE Contact
(
PersonId int not null
,Email varchar(100) null
,SecondaryEmail varchar(100) null
)
INSERT Contact values
(1, null, null)
,(2, 'OnlyFirst', null)
,(3, null, 'OnlySecond')
,(4, 'FirstEmail', 'SecondEmail')
And the following to set the change to make, show contents before, make the change, then show contents after.
DECLARE
#PersonId int
,#Email varchar(100) = 'NewEmail#foo.com'
SET #PersonId = 4
-- Before
SELECT * from Contact
-- Modify
UPDATE Contact
set
Email = #Email
,SecondaryEmail = case when Email is not null then Email else SecondaryEmail end
where PersonID = #PersonID
-- After
SELECT * from Contact
Net result: #Email is always set in column Email, and #SecondaryEmail is set to the contents of Email only if Email was not null