![ER Symbols](/wp-content/uploads/2022/12/ER-Symbols.png)
ER Symbols
- ER model stands for an Entity-Relationship model.
- It is a high-level data model.
- The ER model defines the conceptual view of a database.
- It works around real-world entities and the associations among them.
Symbols | Description |
Entity | |
Weak Entity | |
Relationship | |
Identifying Relationship | |
Attribute | |
Key Attribute | |
Multivalued Attribute | |
Composite Attribute | |
Derived Attribute | |
Total participation of E2 in R | |
Cardinality Ratio 1:N 1E1 entity can be related to NE2 entity | |
Structural Constraint (Min, Max) on participation of E in R | |
Optional One | |
Optional Many | |
Mandatory One |