você pode usar um cursor da seguinte forma:
create trigger trg_insertstuff
on [O_SALESMAN]
after insert
as
DECLARE @SLSMAN_CD NVARCHAR(20)
DECLARE @SLSMAN_NAME NVARCHAR(20)
declare db_cursor CURSOR FOR
SELECT SLSMAN_CD, SLSMAN_NAME
from inserted
OPEN db_cursor
FETCH NEXT FROM db_cursor INTO @SLSMAN_CD , @SLSMAN_NAME
WHILE @@FETCH_STATUS = 0
BEGIN
IF NOT EXISTS(SELECT * FROM O_SALESMAN_USER WHERE SLSMAN_CD = @SLSMAN_CD)
BEGIN
INSERT INTO O_SALESMAN_USER(SLSMAN_CD, PASSWORD, USER_CD)
VALUES(@SLSMAN_CD, @SLSMAN_CD,@SLSMAN_NAME )
END
FETCH NEXT FROM db_cursor INTO @SLSMAN_CD , @SLSMAN_NAME
end
CLOSE db_cursor
DEALLOCATE db_cursor
