SQL Query

this code from "slightwv" expert seems work only for the following table

select guid, linkguid, loannumber, lientype, case when linkguid=prev_guid then prev_code else programcode end new_programcode
from (
   select guid, linkguid, loannumber, lientype, programcode,
      lag(guid) over(order by loannumber asc) prev_guid,
      lag(programcode) over(order by loannumber asc) prev_code
   from junk
) x;

Example:

Guid        LinkGuid     LoanNumber     LienType         ProgramCode
{f1244}  {2077a}       123456789      First Lien         Bond
{2077a} {f1244}        567345673      Second Lien    C30

Result
Guid        LinkGuid     LoanNumber     LienType         ProgramCode
{f1244}  {2077a}       123456789      First Lien         Bond
{2077a} {f1244}        567345673      Second Lien    Bond <-- should change to 'Bond'


if the table like the following then the above code won't work.

Example:

Guid        LinkGuid     LoanNumber     LienType         ProgramCode
{f1244}  {2077a}       123456789      First Lien         Bond
{2077a} {f1244}        567345673      Second Lien    C30
{4ertw}  {w234r}       342342342     First Lien          C15
{w234r} {4ertw}        567834566     Second Lien     C30

Result
Guid        LinkGuid     LoanNumber     LienType         ProgramCode
{f1244}  {2077a}       123456789      First Lien         Bond
{2077a} {f1244}        567345673      Second Lien    Bond <-- should change to 'Bond'
{4ertw}  {w234r}       342342342     First Lien          C15
{w234r} {4ertw}        567834566     Second Lien     C30  <-- no change