sample about take last databackup(data only)in small size

[vpn2012]

I have three database branches in another places but all same structure and tables every thing( A,B,C) what I need is to take every update in databases A,C then put in B

EXAMPLE
Database A:
Employee Table
ID:
Name:
ID Name
12 Ahmed
24 Mohamed
36 Islam

Database B:
Employee Table
ID:
Name:
ID Name
1 Michel
2 Ali
3 Mahmud

Database C:
Employee Table
ID:
Name:
ID Name
11 Nasser
21 Said
31 Sahel
This is daily backup
That I need according to example add extra data that make every day to database B
After updated

Database B:
Employee Table
ID:
Name:
ID Name
1 Michel
2 Ali
3 Mahmud
11 Nasser
21 Said
31 Sahel
12 Ahmed
24 Mohamed
36 Islam
And if any extra data in next day made in A, C Transfer only data that changed or updated in this day to database B
Are you having any solution to solve the problem?
Thanks