PostgreSQL

To use Liam ERD in a PostgreSQL environment, you can simply parse an .sql file generated by commands such as pg_dump --schema-only. Below is a guide on how to create an ER diagram using a PostgreSQL dump file.

Using a pg_dump-generated SQL File

For example, you can dump only the database schema into a file named schema.sql with the following command:

pg_dump --schema-only --file=schema.sql postgres://username:password@hostname:5432/dbname

You may also consider using the following options, because privilege-related statements and owner information are generally unnecessary for ER diagrams:

• --no-privileges: Excludes all privilege-related statements (e.g., GRANT / REVOKE) from the dump.
• --no-owner: Omits ownership statements (e.g., ALTER TABLE ... OWNER TO ...).

Once you have generated schema.sql, you can use Liam CLI to build an ER diagram.
Specify --format postgres and --input schema.sql as follows:

npx @liam-hq/cli erd build --format postgres --input schema.sql

If the above command runs successfully, an ER diagram will be generated.

Under the Hood

For parsing PostgreSQL SQL files, Liam CLI relies on the following libraries:

• pganalyze/pg-query-emscripten
• pganalyze/libpg_query