In case of an SQL injection where the result will be visible through another resource, use a second order injection. It is even possible to use a script in beforehand to login in and get a cookie, for example. A tutorial can be found on [Le Thanh Phuc's blog](https://lethanhphuc-pk.medium.com/second-order-sql-injection-explained-with-example-f67fb199f5e5)
An example oneliner including a tamper script and a first and second request captured in Burpsuite
The `second_order_tamper.py` can be found inside this repository. Users are created through this script by SQLmap to further login through `login.request` and read the output through `second.req` (delete the cookie from the header). The vulnerable POST parameter is `username`.