In a bowl, combine the cornmeal, salt, sugar, baking powder, and baking soda. Whisk together to combine well.
In a large bowl, combine the buttermilk, eggs, and creamed corn, whisking together to combine thoroughly. Add the dry ingredients to the buttermilk mixture and stir to combine. If the batter will not pour, add more buttermilk to the batter.
Swirl the canola oil in the hot cast iron skillet. Pour the batter into the skillet. Bake until the cornbread is golden brown and springs back upon the touch, about 20 minutes.