parsegres

PostgreSQL-compatible SQL parser library written in pure Crystal

Parsegres

Parsegres provides a Postgres-compatible SQL parser.

Installation

  1. Add the dependency to your shard.yml:

    dependencies:
  parsegres:
    github: jgaskins/parsegres

  2. Run shards install

Usage

The main use case is to parse a SQL query using the Parsegres.parse method:

require "parsegres"

query = Parsegres.parse(<<-SQL)
  SELECT *
  FROM users
  WHERE status = $1
  AND group_id = $2
  LIMIT 25
SQL

Supported statements

Statement Notes
SELECT CTEs, set operations (UNION, et al), subqueries, JOINs, window functions
INSERT VALUES, DEFAULT VALUES, INSERT … SELECT, RETURNING
UPDATE FROM, RETURNING
DELETE USING, RETURNING
CREATE TABLE Column/table constraints, TEMP, IF NOT EXISTS, schema-qualified
ALTER TABLE {ADD,DROP,ALTER,RENAME} COLUMN, ADD/DROP CONSTRAINT
DROP TABLE IF EXISTS, CASCADE/RESTRICT, multiple tables
CREATE INDEX UNIQUE, CONCURRENTLY, USING, partial indexes, IF NOT EXISTS
DROP INDEX CONCURRENTLY, IF EXISTS, multiple indexes
CREATE VIEW OR REPLACE, TEMP, IF NOT EXISTS, explicit column list
DROP VIEW IF EXISTS, CASCADE/RESTRICT, multiple views
TRUNCATE Multiple targets, ONLY, RESTART/CONTINUE IDENTITY, CASCADE/RESTRICT
CREATE SEQUENCE All standard options (INCREMENT BY, MINVALUE/MAXVALUE, START, CACHE, CYCLE, OWNED BY)
ALTER SEQUENCE Same options as CREATE SEQUENCE, plus RESTART
DROP SEQUENCE IF EXISTS, CASCADE/RESTRICT, multiple sequences
CREATE SCHEMA IF NOT EXISTS, AUTHORIZATION
DROP SCHEMA IF EXISTS, CASCADE/RESTRICT, multiple schemas
CREATE EXTENSION IF NOT EXISTS
DROP EXTENSION IF EXISTS, CASCADE/RESTRICT, multiple extensions
CREATE TYPE Range types (AS RANGE)
CREATE RULE OR REPLACE, event routing, DO ALSO/DO INSTEAD
DO Anonymous code blocks, optional LANGUAGE
BEGIN Optional WORK/TRANSACTION
COMMIT Optional WORK/TRANSACTION
ROLLBACK Optional WORK/TRANSACTION

Not yet implemented

The following statement types are not currently supported. PRs welcome!

  • CREATE TYPE — composite types, enums, domains (range types are supported)
  • DROP TYPE — dropping types
  • GRANT / REVOKE — privilege management
  • CREATE FUNCTION / DROP FUNCTION — user-defined functions
  • CREATE TRIGGER / DROP TRIGGER — trigger management
  • CREATE MATERIALIZED VIEW / REFRESH MATERIALIZED VIEW / DROP MATERIALIZED VIEW
  • ALTER VIEW — modifying existing views
  • ALTER SEQUENCE advanced options — OWNED BY reassignment, AS type
  • SAVEPOINT / RELEASE SAVEPOINT / ROLLBACK TO SAVEPOINT
  • LOCK TABLE
  • VACUUM / ANALYZE
  • COPY
  • EXPLAIN

Contributing

  1. Fork it (https://github.com/jgaskins/parsegres/fork)
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Contributors

Repository

parsegres

Owner
Statistic
  • 0
  • 1
  • 3
  • 0
  • 0
  • 5 days ago
  • February 23, 2026
License

MIT License

Links
Synced at

Thu, 05 Mar 2026 05:17:12 GMT

Languages
Crystal 100.0%