End-users interact with databases through queries, which are requests for specific data or actions.There are several methods for querying databases, each catering to different user needs and technical expertise.SQL (Structured Query Language)SQL is a powerful language used to manage and manipulate relational databases.It allows users to perform tasks such as retrieving data, updating records, and managing database structures.Many database management systems support SQL, making it a universal tool for database interaction.ExampleSELECT * FROM Students WHERE Grade > 90; TipSQL is widely used because it is both powerful and relatively easy to learn.QBE (Query By Example)QBE is a graphical query language that allows users to build queries by providing examples of the data they seek.It is designed for users who may not be familiar with SQL syntax.It is often used in educational settings and by non-technical users.ExampleFieldStudentIDNameGradeTable StudentsStudentsStudentsShow✓✓✓Criteria> 90TipQBE is user-friendly and reduces the likelihood of syntax errors.Visual QueriesVisual queries use graphical interfaces to help users construct queries without writing code.These interfaces often include drag-and-drop features, checkboxes, and dropdown menus.They are commonly found in modern database management tools and software applications.ExampleA user selects the "Students" table, checks the "Name" and "Grade" columns, and sets a filter for "Grade > 90." TipVisual queries are ideal for beginners and those who prefer a more intuitive approach.