SQL & PL/SQL

Hi all,

I have to include a statement in a query which allows to compare the current value of column A with the previous value of column A (same column). from there, I need to add a condition in order to have the expected result.
Let's take an example to illustrate what I want to achieve:

I have the following columns in table called 'Charges':

Ship_id batch_nr Order_nr Price
SID1111 9997 MD5551 50
SID1111 9998 MD5552 50
SID1111 9999 MD5553 50
SID2222 8887 MD6661 80
SID2222 8887 MD6662 80
SID2222 8887 MD6662 80
SID3333 6666 MD7771 90

I want to check if the ship_id of row 2,3 (and more if available) is equal to the ship_id of row 1.
If it is the case, then value 'together with the first batch_nr' in row 2 and 3 under Price column. If not, then keep the original value of Price column
PLease see below the expected result:
Ship_id batch_nr Order_nr Price
SID1111 9997 MD5551 50
SID1111 9998 MD5552 together with 9997
SID1111 9999 MD5553 together with 9997
SID2222 8887 MD6661 80
SID2222 8887 MD6662 together with 8887
SID2222 8887 MD6663 together with 8887
SID3333 6666 MD7771 90

Thanks in advance for your help, it is really urgent.

Imco20030