Plugging in entire questions or statements into a database isn't the best strategy. This is because the database looks for each word you include. The more words, the fewer potential matches. Typically, the database will look for the words in the information about an article, including its title, abstract (summary), and in the tagged subjects (these are, essentially, the article's hashtags.)
Since all the database does is look for instances of the words you plug into the search box, similar to the Ctrl+F shortcut, it's best to use a few words that get at the heart of your topic.
Not all authors use the same language to describe similar topics, so you will need to try a variety of searches to capture relevant results.
Let's say you want to learn more about licensed vocational nurses.
Besides searching "licensed vocational nurse," what are other related terms you could search for that are similar?