You can use the advanced search features of the normal site - no need for fancy database queries. It's not so easy to find, but there is a little "Advanced Search Tips" whenever you search and some of these features are relevant for you.
First you go to your profile on the main site. That's here. As you can see the searchbar is already filled with your user-id. No need to search for that somewhere. The searchbar reads user:12102, which will give you all posts from you.
Next we want to limit this down to questions. There is a handy way to do this: just add "is:question" or in short "is:q" to the searchbar. Like here (1296 posts from you are questions - impressive!).
Next we want to limit this down to all those with an accepted answer: "hasaccepted:yes" => user:12102 hasaccepted:yes (912 of your questions have an accepted answer).
Together those two search queries mean that you have accepted an answer in 912 / 1296 ~ 70% of all cases where you asked a question.
Minor addition: those are only undeleted questions, I don't know if you have deleted ones.
If you want to find those without an accepted answer you can just change the query to "hasaccepted:no" like here, for example in case you want to search for interesting questions that you want to offer a bounty on.