Cleaning T-SQL tables - sql-server

Question

I'm new to T-SQL and trying to do some cleanup on some data imported from Excel into SQL Server.
I have made a batch import that imports the raw data to a staging table and now I want to clean it up.
I have the following tables
tblRawInput (my stageing table):
Name, Name2, Name3, Phonenumber, Group
tblPeople:
PersonID (IDENTITY), Name, Phonenumber, GroupID
tblGroups:
GroupID (IDENTITY), Groupname
tblAltNames:
NameID (IDENTITY), Name, PersonID
The query should be able to split the data into the other tables, but not create a group if it already exists.
I am at a loss. Could anyone give me a pointer in the right direction.
When I do a SELECT INTO it creates multiple copies of the groups.

Answer 1

You can use a not exists clause to insert only new groups:
insert into Groups
(GroupName)
select distinct Group
from tblRawInput ri
where not exists
(
select *
from Groups
where g.GroupName = ri.Group
)
After this, you can insert into tblPeople like;
insert tblPeople
(Name, GroupID)
select ri.Name
, g.GroupID
from tblRawInput ri
-- Look up GroupID in the Groups table
join Groups g
on g.GroupName = ri.Group
You can do the alternate names along the same lines.

Answer 2

First in this case order matters. Insert to groups first.
insert into tblGroups
(GroupName)
select Group
from tblRawInput ri
where not exists
(
select *
from tblGroups g
where g.GroupName = ri.Group
)
Then insert to the people table
Insert into tblPeople(Name, Phonenumber, GroupID)
Select Name, Phonenumber, GroupID
from tblRawInput ri
join tblGroups g
on g.groupName = ri.group
where not exists
(
select *
from tblPeople p
where p.Name = ri.Name
and p.Phonenumber = ri.Phonenumber
and p.groupId = g.groupid
)
Then get the alt name
Insert into tblAltNames (Name, Personid)
Select Distinct Name2, PersonID
from tblRawInput ri
join tblPerson p
on p.Name = ri.Name
where not exists
(
select *
from tblAltNames p
where p.Name = ri.Name2
)
Of course all of this should be wrapped in a transaction and a try catch block with a rollback of everything is one of the inserts fails.
Possibly the second query shoudl use the output clause to get teh personids inserted instead of the join. You don't really have anything good to join on here because names are not unique.