erd: An entity-relationship diagram generator from a plain text description.

[ database, development, program, public-domain ] [ Propose Tags ]

erd transforms a plain text description of a relational database schema to a graphical representation of that schema. It is intended that the graph make use of common conventions when depicting entity-relationship diagrams, including modeling the cardinality of relationships between entities.

A quick example that transforms an er file to a PDF is just below. The original source file can be found amongst the examples in the repository.

$ cat
# Entities are declared in '[' ... ']'. All attributes after the
# entity header up until the end of the file (or the next entity
# declaration) correspond to this entity.


# Each relationship must be between exactly two entities, which
# need not be distinct. Each entity in the relationship has
# exactly one of four possible cardinalities:
# Cardinality    Syntax
# 0 or 1         0
# exactly 1      1
# 0 or more      *
# 1 or more      +
Person *--1 Location
$ erd -i -o simple.pdf

The PDF should now contain a graph that looks like this:

See the file for more examples and instructions on how to write ER files.


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Change log
Dependencies base (>=4.5 && <5), bytestring (>=0.10 && <0.11), containers (>=, directory (>=, filepath (>=1.4.2), gitrev (>=1.3.1), graphviz (>=2999.20 && <2999.21), parsec (>=3.1 && <3.2), raw-strings-qq (>=1.1), text (>=1 && <2), yaml (>=0.8.32) [details]
License LicenseRef-PublicDomain
Author Andrew Gallant
Category Database, Development
Home page
Source repo head: git clone git://
Uploaded by mmzx at 2020-02-02T11:59:04Z
Reverse Dependencies 1 direct, 0 indirect [details]
Executables erd
Downloads 6754 total (42 in the last 30 days)
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Status Docs not available [build log]
Last success reported on 2020-02-02 [all 3 reports]