Entity Relationship Diagram Symbol Legend

Entity relationship diagram symbol legend provides the most frequently used symbols and shapes for making ER diagram. It’s a comprehensive symbol collection including all entity relationship symbols, chen ERD symbols, Martin ERD symbols, Express G symbols and ORM symbols.

ER Diagram Symbols

Entity
Entity 2
Entity 3
View
Relationship
Entity
Entity 2
Entity 3
View
Relationship
Parent to Category
Category
Category to Child
Dynamic Connector
Line Connector
Parent to Category
Category
Category to Child
Dynamic Connector
Line Connector
Entity 5
Strong Entity
Weak Entity
Strong Relationship
Weak Relationship
Entity 5
Strong Entity
Weak Entity
Strong Relationship
Weak Relationship
Attribute
Derived Attribute
Multi-valued Attribute
Constraints
Cardinality
Attribute
Derived Attribute
Multi-valued Attribute
Constraints
Cardinality
Partial
Weak line
Participation
Participation 2
Partial
Weak line
Participation
Participation 2

Chen ERD Symbols

Entity with items
Entity with items 2
User
Relationship
Entity
Entity with items
Entity with items 2
User
Relationship
Entity
Attribute
Aggregation
Line connector
Double line connector
One to many caption
Attribute
Aggregation
Line connector
Double line connector
One to many caption
Many to many caption
One to one caption
Variable to variable
Many to many caption
One to one caption
Variable to variable

Martin ERD Symbols

Data entity
Activity entity
Data item
Connection
Event
Data entity
Activity entity
Data item
Connection
Event
Square loop
And or branch
Top to bottom
Side to top
Side to side
Square loop
And or branch
Top to bottom
Side to top
Side to side
One
Many
One or more
Zero or one
One or more 2
One
Many
One or more
Zero or one
One or more 2
Zero or more
One and only one
Zero or one 2
Zero or more
One and only one
Zero or one 2

Express-G Symbols

Entity
Base type
Enumerate type
Defined type
Select type
Entity
Base type
Enumerate type
Defined type
Select type
Boundary
Pointer
Cardinality
Inverse cardinality
Normal relationship
Boundary
Pointer
Cardinality
Inverse cardinality
Normal relationship
Tree structure
Relationship pointer
Subtype
Schema
Used entity
Tree structure
Relationship pointer
Subtype
Schema
Used entity
Referenced entity
To page reference
From page reference
Label
Page reference
Referenced entity
To page reference
From page reference
Label
Page reference

ORM Diagram Symbols

Entity
Value
Unary
Binary
Vertical binary
Entity
Value
Unary
Binary
Vertical binary
Ternay
Quaternary
Exclusion constraint
Ext.Freq.constraint
Frequency constraint
Ternay
Quaternary
Exclusion constraint
Ext.Freq.constraint
Frequency constraint
Index annotation
Ext.P constraint
Mandatory constraint
Ext.Mand constraint
Ext.Uniq constraint
Index annotation
Ext.P constraint
Mandatory constraint
Ext.Mand constraint
Ext.Uniq constraint
constraint connector
Equality constraint
P constraint
Ring constraint
Subset constraint
constraint connector
Equality constraint
P constraint
Ring constraint
Subset constraint
Mand.Role connector
Role connector
Subtype connector
Left uniqueness constranit
Uniqueness constraint
Mand.Role connector
Role connector
Subtype connector
Left uniqueness constranit
Uniqueness constraint
Middle uniqueness constraint
Right uniqueness constraint
Middle uniqueness constraint
Right uniqueness constraint

How to Use ER Diagram Symbols

Edraw contains every ER symbol that program developers need. The symbols are right in the software library pane, which can be used through drag-and-drop. You can also modify the symbol size, color and text according to your specific requirements. Edraw has the ability to create nice ER diagrams not only through built-in symbols, but also with professional tools, templates and examples.

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