pgviz

visualize foreign-key relations in postgresql

This program produces diagrams of graphs where the nodes are tables and the edges are foreign-key relations. There is a small query language to specify the tables that should be included in the diagram.

Using the Pagila schema as an example:

pgviz --out pagila.svg "(graph (within 2 (table film)))"

produces

Query language

The query language uses s-expressions and includes the following functions:

graph <q: query> <s0: subgraph> ...

produces a graph with top level nodes matching q and any number of included subgraphs

subgraph <label: string> <g: graph> ...

produces a subgraph with the provided label that contains the provided graph

within <n: integer> <q: query>

produces a query that includes all tables within n edges of tables matching q

schema <s: schema name> ...

produces a query that includes all tables contained by the provided schemas

table <t: table name> ...

procudes a query that includes tables whose name is equal to any of the provided table names

and <q0: query> <q1: query> ...

produces a query that include tables that match all of the provided queries

or <q0: query> <q1: query> ...

produces a query that includes tables that match any of the provided queries

- <lhs: query> <rhs: query>

produces a query that includes tables that match lhs, but do not match rhs

Colors

Columns have background colors that indicate certain attributes, for example: nullable columns are gray, unique columns are green, primary key columns are blue, columns that are both nullable and unique are a darker green.

Installation

Cargo

cd into src and cargo build as usual. graphviz is a runtime dependency.

Nix

nix build will compile the binary that references a nix-pinned graphviz. You can also run it directly with

nix run "github:tstat/pgviz" -- <args>

or add it to your nix registry with

nix registry add pgviz "github:tstat/pgviz"

then you can run it with nix run pgviz -- <args>