SQL Server 2017

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create table table1 (id int, Attribute varchar(50) , Value  varchar(50));

insert into table1 values(101     ,'Manager'     ,'Rudolf');   
insert into table1 values(101     ,'Account'     ,'456');   
insert into table1 values(101     ,'Code'        ,'B');
insert into table1 values(102     ,'Manager'     ,'Anna');
insert into table1 values(102     ,'Cardno'      ,'123');
insert into table1 values(102     ,'Code'        ,'B');
insert into table1 values(102     ,'Code'        ,'C');
7 rows affected

select *  
from
(
    select t1.id,t1.attribute,
    string_agg(value,',')  AS value
    from table1 t1
    group by t1.id,t1.attribute
) d
pivot
(
  max(value)
  for attribute in (manager,account,cardno,code)
) piv


id
manager
account
cardno
code


101
Rudolf
456
null
B

102
Anna
null
123
B,C


select *  
from
(
    select distinct t1.id,t1.attribute,
  STUFF(
         (SELECT ', ' + convert(varchar(10), t2.value, 120)
          FROM table1 t2
          where t1.id = t2.id and t1.attribute=t2.attribute
          FOR XML PATH (''))
          , 1, 1, '')  AS value
from table1 t1
) d
pivot
(
  max(value)
  for attribute in (manager,account,cardno,code)
) piv


id
manager
account
cardno
code


101
 Rudolf
 456
null
 B

102
 Anna
null
 123
 B, C