University Student Enrollment ER diagram models a complete academic database with STUDENT as the root entity, specialized into UNDERGRADUATE and GRADUATE via inheritance, connected to COURSE, SECTION, INSTRUCTOR, and an ENROLLMENT associative entity. Data flows from STUDENT through ENROLLMENT to SECTION, which references both COURSE and INSTRUCTOR, capturing the full enrollment lifecycle. This design enforces referential integrity and supports queries across student demographics, course offerings, and enrollment records—essential for registrar systems managing thousands of enrollments. Fork this diagram on Diagrams.so to customize entity attributes, add constraints, or export as SQL schema documentation. The ISA (specialization) pattern elegantly separates student-type-specific fields like major and thesis_topic while maintaining a single STUDENT primary key.