Notations

⚠️ Multi-notation support is still an experimental feature!

Supported Notations:

• Bachman
• Crow's Foot
• Chen
• UML

The notation can be changed in the header of .erd files:

erdiagram Example

// options can be in any order
generate=off   
notation=default

// elements ...

The default option is used if the notation is not specified.

Default

Option: default

The default option is currently the only notation that is supported for generating SQL code (generate=sql). Valid relationships for code generation are One 1 or Many N relationships.

Syntax	Description	Diagram
A or A[]	None
A[1]	One
A[N]	Many
A["abc"]	Custom
A[min,max]	Between min and max
A[min,*]	Between min and no bound

Bachman

Syntax	Description	Diagram
A[0]	?
A[0+]	?
A[1]	?
A[1+]	?

Crow's Foot

Syntax	Description	Diagram
A[?]	Zero or One
A[0+]	Zero or More
A[1]	One and only One
A[1+]	One or More

Chen

Syntax	Description	Diagram
A[1]	One
A[N]	Many

UML

⚠️ TODO