Restrict a user to specific rows in a table.
For example, allow an employee to see only the rows recording his or her work in a labor-tracking table.
Restrict a user to specific columns.
For example, allow employees who do not work in payroll to see the name, office, work phone, and department columns in an employee table, but do not allow them to see any columns with salary information or personal information.
Join columns from multiple tables so that they look like a single table.
Aggregate information instead of supplying details.
For example, present the sum of a column, or the maximum or minimum value from a column.