Link to home
Start Free TrialLog in
Avatar of cottage125
cottage125

asked on

Insert into

create table dba.tbl_member (member_name varchar(20))
create table dba.tbl_donor  (donor_name varchar(20))

INSERT INTO dba.tbl_member Values ( 'USA')
INSERT INTO dba.tbl_member Values ( 'CANADA')
INSERT INTO dba.tbl_member Values ( 'MEXICO')

INSERT INTO dba.tbl_donor Values ( 'USA')
INSERT INTO dba.tbl_donor Values ( 'ASIA')
INSERT INTO dba.tbl_donor Values ( 'BRAZIL')

select * from dba.tbl_member
select * from dba.tbl_donor

-- Now I need to insert all donor_name values from dba.tbl_donor to member_name.tbl_member table.
-- BUT IF the same name already exists in dba.tbl_member then prefix it with 'DL-' and insert else insert the name from 2nd to first table.
-- So here USA exists in both tables so insert 'DL-USA' in dba.tbl_member and then the rest 2 rows.

INSERT INTO dba.tbl_member (member_name)
(SELECT CASE WHEN a.donor_name =b.member_name THEN 'DL-' + substring(a.donor_name, 1, LEN(a.donor_name))  
ELSE a.donor_name END AS member_name FROM dba.tbl_donor a,dba.tbl_member b) -- BUT I THINK MY THIS QUERY NEEDS YOUR HELP
FROM dba.tbl_donor

So for this scenario I should be able to see total 6 rows in dba.tbl_member after insert.
Avatar of TempDBA
TempDBA
Flag of India image

You can use outer join for this.

INSERT INTO dba.tbl_member (member_name)
SELECT
           CASE WHEN b.member_name is null
                       THEN 'DL-' + a.donor_name
                       ELSE a.donor_name
           END AS member_name
FROM dba.tbl_donor a
left outer join dba.tbl_member b
on a.donor_name = b.member_name
Avatar of cottage125
cottage125

ASKER

ITs giving wrong results see below,  thats now what I want.
member_name
'DL-ASIA'
'DL-BRAZIL'
'USA'

But I want,

member_name
'ASIA'
'BRAZIL'
'DL-USA'
try

INSERT INTO dba.tbl_member (member_name)
select case when b.member_name is null then a.donor_name else 'DL -' + a.donor_name end
FROM dba.tbl_donor a
left outer join dba.tbl_member b on a.donor_name = b.member_name
<<-- BUT IF the same name already exists in dba.tbl_member then prefix it with 'DL-' and insert else insert the name from 2nd to first table.
-- So here USA exists in both tables so insert 'DL-USA' in dba.tbl_member and then the rest 2 rows.>>

I thought that's what you wanted. Anyway, Just reverse the case statemetn

INSERT INTO dba.tbl_member (member_name)
SELECT
           CASE WHEN b.member_name is not null
                       THEN 'DL-' + a.donor_name
                       ELSE a.donor_name
           END AS member_name
FROM dba.tbl_donor a
left outer join dba.tbl_member b
on a.donor_name = b.member_name
or even simpler

INSERT INTO dba.tbl_member (member_name)
select coalesce('DL -' + b.member_name, a.donor_name)
FROM dba.tbl_donor a
left outer join dba.tbl_member b on a.donor_name = b.member_name
Okay Thats but is there any way I can use if exist or someting like that and dont use any joins?? Just wondering.
>> if exist or someting like that and dont use any joins?? Just wondering. <<

Why would you do that? The above suggestions are more efficient than using exists
ASKER CERTIFIED SOLUTION
Avatar of Anthony Perkins
Anthony Perkins
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial