Homepage: https://github.com/magit/emacsql
Author: Christopher Wellons
Updated:
High-level SQL database front-end
EmacSQL is a high-level Emacs Lisp front-end for SQLite
(primarily), PostgreSQL, MySQL, and potentially other SQL
databases. On MELPA, each of the backends is provided through
separate packages: emacsql-sqlite, emacsql-psql, emacsql-mysql.
Most EmacSQL functions operate on a database connection. For
example, a connection to SQLite is established with
`emacsql-sqlite'. For each such connection a sqlite3 inferior
process is kept alive in the background. Connections are closed
with `emacsql-close'.
(defvar db (emacsql-sqlite "company.db"))
Use `emacsql' to send an s-expression SQL statements to a connected
database. Identifiers for tables and columns are symbols. SQL
keywords are lisp keywords. Anything else is data.
(emacsql db [:create-table people ([name id salary])])
Column constraints can optionally be provided in the schema.
(emacsql db [:create-table people ([name (id integer :unique) salary])])
Insert some values.
(emacsql db [:insert :into people
:values (["Jeff" 1000 60000.0] ["Susan" 1001 64000.0])])
Currently all actions are synchronous and Emacs will block until
SQLite has indicated it is finished processing the last command.
Query the database for results:
(emacsql db [:select [name id] :from employees :where (> salary 60000)])
;; => (("Susan" 1001))
Queries can be templates -- $i1, $s2, etc. -- so they don't need to
be built up dynamically:
(emacsql db
[:select [name id] :from employees :where (> salary $s1)]
50000)
;; => (("Jeff" 1000) ("Susan" 1001))
The letter declares the type (identifier, scalar, vector, Schema)
and the number declares the argument position.
See README.md for much more complete documentation.