Active Query Builder is a component for software developers to give end-users without any experience in SQL language the ability to create SQL queries via the intuitive drag'n'drop interface. Same time it allows experienced users to analyze their queries visually by parsing them and building the visual diagram. Active Query Builder substitutes tedious typing with natural point-and-click actions, helps to avoid common pitfalls, enables preview the result sub-query data to understand and debug complex SQL queries.