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.
Microsoft SQL ServerSybase DatabaseMySQL Server

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Last Comment
Anthony Perkins

8/22/2022 - Mon
TempDBA

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
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'
ralmada

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
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William Peck
TempDBA

<<-- 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
ralmada

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
cottage125

ASKER
Okay Thats but is there any way I can use if exist or someting like that and dont use any joins?? Just wondering.
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ralmada

>> 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
Anthony Perkins

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