PGmacs provides an editing interface for the PostgreSQL 🐘 object-relational DBMS from Emacs. It allows you to:

• browse the list of tables in the database

• browse the contents of a table, row by row, in paginated mode for large tables, and navigate between tables if they are linked by a foreign key

• edit the value of a column: type RET on the value you want to modify to edit the value in the minibuffer, or type w to edit the value in a widget-based buffer

• insert new rows into the table: type + in a table buffer to insert a row with new values obtained from the minibuffer, or type i to insert a new row with values obtained from a dedicated widget-based buffer.

• delete a row: type DEL in a table buffer to delete the row at point

• copy/paste rows of a database table (type k to copy, y to paste in a table display buffer)

• save the contents of a table in CSV or TSV format, or the contents of a row in JSON format

It works both in the terminal (TUI) and in GUI mode.

📖 You may be interested in the user manual.

In your Emacs initialization file, include the following to check out the latest version of the code from the git repository, as well as the pg-el dependency:

;; Requires Emacs 29 and git
(unless (package-installed-p 'pg)
   (package-vc-install "https://github.com/emarsden/pg-el" nil nil 'pg))
(unless (package-installed-p 'pgmacs)
   (package-vc-install "https://github.com/emarsden/pgmacs"))

(require 'pgmacs)

You can later upgrade these to the latest version with M-x package-vc-upgrade RET pgmacs RET. See the user manual for more installation methods (for example using use-package).

To load PGmacs, say

M-x pgmacs

which will open a widget-based buffer to collect connection information (database name, hostname, port, etc.). It will then open the PGmacs main buffer, which will show you a list of the tables available in the database.

You can also open PGmacs with a PostgreSQL connection string

M-x pgmacs-open-string RET user=myself port=5432 dbname=mydb

or with a PostgreSQL connection URI

M-x pgmacs-open-uri RET postgresql:https://%2Fvar%2Flib%2Fpostgresql/dbname

or with a connection object from the pg.el library (function pgmacs-open). Check the user manual for more.

PGmacs is in beta status. As of 2024-07, the author has sufficient confidence in the code to use it to modify real PostgreSQL databases used in production.

Emacs version: PGmacs requires Emacs version 29. It has also been tested on the pre-release v30. It has mostly been tested on Linux, but should work as expected on Microsoft Windows and MacOS. It works both in graphical mode and in the terminal.

PostgreSQL version: PGmacs is primarily tested with PostgreSQL versions 17.0 and 16.4, but should work with any PostgreSQL version supported by the pg-el library that it uses to communicate with PostgreSQL. For example, it works fine with PostgreSQL version 14 which was released in 2021.

PGmacs also works with some databases that implement the PostgreSQL wire protocol, but not with all of them. PGmacs queries various internal PostgreSQL tables for metainformation on the list of tables available, and these tables are not always present in PostgreSQL-compatible databases. PGmacs also uses some PostgreSQL-specific functions to display information such as the on-disk size of tables, and these functions are not always implemented. What we have tested so far:

• Neon “serverless PostgreSQL” works perfectly.

• ParadeDB v0.9.1 seems to work fine in limited testing (it's really a PostgreSQL extension rather than a fully separate product).

• The Timescale DB extension for time series data works perfectly (tested with version 2.16.1).

• The IvorySQL Oracle-compatible flavour of PostgreSQL works perfectly (last tested with version 3.4).

• Xata “serverless PostgreSQL” has many limitations including lack of support for CREATE DATABASE, CREATE COLLATION, for XML processing, for temporary tables, for cursors, for EXPLAIN, for CREATE EXTENSION, for functions such as pg_notify.

• YugabyteDB v2.23 works to a limited extent: we are not able to run the SQL command that adds a PRIMARY KEY to an existing table, nor to display total database size on disk, for example.

• CrateDB v5.8.3 does not currently work; it does not implement PostgreSQL functions that we use to query table metainformation.

• CockroachDB version 24.2 does not work with PGmacs: our query for pg-table-owner triggers an internal error, there is no implementation of the function pg_size_pretty, and the database fails on basic SQL such as the boolean vector syntax b'1001000'.

• QuestDB: tested against version 6.5.4. This has very limited PostgreSQL support, and does not support the integer type for example.

• Google Spanner, or at least the Spanner emulator (that reports itself as PostgreSQL 14.1) and the PGAdapter library that enables support for the PostgreSQL wire protocol, do not work with PGmacs. Spanner has only limited PostgreSQL compatibility, for example refusing to create tables that do not have a primary key. It does not implement some functions we use to query the current user and database status, such as current_user, pg_backend_pid, pg_is_in_recovery.

• YDB by Yandex version 23-4 has very limited PostgreSQL compatibility and does not work with PGmacs. The system tables that we query to obtain the list of tables in the current database are not implemented.

• ClickHouse v24.5 does not work: its implementation of the wire protocol is very limited, with no support for the pg_type metadata and no support for basic PostgreSQL-flavoured SQL commands such as SET.

PGmacs is distributed under the terms of the GNU General Public License, version 3.

Copyright 2023-2024 Eric Marsden.