Code to update or insert if doesnt exist

I have 2 worksheets. A master and a monthly update. Both contain student number (primary key) and fields like address, phone number, etc. I am trying to update the master sheet with any changes from the monthly file or insert a row if it is a new student. So for example if student 1 exists but has a new phone number it will update that cell, if student 1000 does not exist in the master it will insert a new row.

Both sheets have the exact same format and same column headers. In SQL I would do a normal update/insert process but is there an easy way to loop through and perform the same in VBA?

Thank you in advance!

I think it is fairly straightforward. Sheet 1 (aka master) has columns studentid, name, address, city, state, .....; Sheet 2 (aka 2015 updates) has same columns studentid, name, address, city, state. VBA code would read through Sheet 2, find the matching student in sheet1 and update name, address, city, state, etc. If no matching student is found in sheet1, then the new student would be inserted into sheet1.
Does that make sense? Is that straightforward enough or do I need to mock up a excel doc?
Thank you very much in advance for your help!

Thank you. I am in the process of testing it and will let you know. Thank you for taking the time to help.

One question I was wondering about is if in the future I decided to only update/insert columns A-E for example is there an easy way to change "ID.EntireRow.Copy mSh.Cells(Lr, 1)" to just update a particular range?

Thanks.

Looks like I am getting a "application defined or object defined error". Could it be that 'LR' is not defined nor populated? the error appears on the first record and on line...."ID.EntireRow.Copy mSh.Cells(Lr, 1) 'updating the current record."

Thank you

Thank you very much, this seems to be working great. I have one more question that happens occasionally but maybe this code could handle it. Both these spreadsheets have the same column names. Is it possible to change the update/insert to insert/update all the columns in the '2015 update' sheet? So for example if the update sheet was missing 'state', then the address, city, etc would still update. I usually check the 'update sheet' to make sure all the columns match and in same order but maybe this code can read the column names in '2015 update' and update the matching column/cell in the master sheet?

Thank you again for all your help!!