SQL Security :: Making Data Change In Read Only Database Without Letting Other Users Update Data

I want to make data changes in read_only database , that's why i must set database read_write. While database is at read_write mode, i want to be sure that no one makes change in database.

For this aim, i write the code below, but i suspect that after setting the database read_write, till the setting database
single_user ,is it possible get DML script from another user. Is the code below enough for this operation. Or is there another way?

Reminding: Read_only database can not be set single_user mode. That's why, first you must set database read_write.

The code;

use master
alter database xxx set read_write
with rollback immediate
alter database xxx set single_user
with rollback immediate

use xxx
update  tablexxx set columnxxx=yyy
use master
alter database xxx set read_only
with rollback immediate
alter database xxx set multi_user
with rollback immediate