Preheat oven to 400 degrees F. In a small bowl mash the beans with a fork or potato masher. Place pizza shell on a baking sheet. Spread the mashed beans evenly over shell; set aside.
In a large skillet heat 1 teaspoon of the olive oil over medium-high heat. Add eggplant, zucchini, onion, and garlic; cook and stir about 5 minutes or until vegetables begin to soften. Remove from heat. Stir in tomatoes, olives, and feta cheese.
In a small screw-top jar combine the remaining 3 teaspoons olive oil, the lemon juice, oregano, sugar, salt, and pepper. Cover and shake well. Add to eggplant mixture; toss to coat.
Spread eggplant mixture over pizza shell to within inch of edges. Sprinkle with shredded cheese. Bake for 16 to 18 minutes or until cheese begins to brown. Cut pizza into 6 slices.