Determining a person’s age from their date of birth within a database is a common requirement in many applications. Structured Query Language (SQL) provides several functions to perform this calculation, typically involving the current date and the stored birth date. For example, some database systems offer dedicated age calculation functions, while others might require using date difference functions and potentially further processing to express the result in desired units (years, months, etc.). An example using date difference could involve subtracting the birth date from the current date, yielding an interval which can then be converted to years.
This capability is essential for applications needing to segment users by age, enforce age restrictions, generate age-based reports, or personalize content. Historically, before dedicated database functions, this process often involved more complex manual calculations or external scripting. Direct implementation within SQL simplifies queries, improves performance, and ensures consistent calculation logic across applications. Accurate age determination facilitates legal compliance, targeted marketing, demographic analysis, and other data-driven decisions.