sqlmap not only figures out how to dump the DB, they even provide a handy "shell" mode that parses SQL, converts it into an injection payload, and executes it on the server. It feels just like having a mysql or sqlite etc. shell. It even supports things like reading files and executing commands (!) if the server supports them (and if the DB user has the appropriate credentials).
Even better, it knows how to exploit blind SQLi and has a number of tricks for doing so: it can often tell if a query is succeeding or failing based on HTTP error codes, and it will do things like try various SLEEP() injections to see if it can hang the server. If it finds any blind SQLi opportunities, it has the ability to dump the entire database *one bit at a time* by just doing a ton of requests in parallel.
You can actually hand it a file full of HTTP request headers and it'll automatically figure out where the potential injection points are, and send a bunch of requests formatted identically to the provided headers. You can practically automate SQL injection testing with a suitable MITM proxy and some scripting.
It has options for disguising requests, for bypassing WAFs, for submitting requests using custom protocols, and a ton more. Just a really well designed tool overall.