Most WordPress themes and plugins look for ways to create lists of posts based on multiple conditions and criteria. You often need to determine what you need on a page and pulls posts accordingly. You may also need to use other information from the requests if you wish to create optimized pages. The WordPress database stores all data for posts, pages, comments, categories, tags, custom fields, users, site URLs etc. If we need more information on these then we need a way to extract this from the database. Writing direct SQL queries is not easy and not recommended. In this cheat sheet, we primarily look at the WordPress functions that provide an easy and reliable way to work with the database.