lex-postgres

A LegionIO extension (LEX) that connects LegionIO to PostgreSQL databases via the pg gem.

Installation

Add to your Gemfile:

gem 'lex-postgres'

Standalone Usage

require 'lex-postgres'

client = Legion::Extensions::Postgres::Client.new(
  host:     'db.example.com',
  port:     5432,
  dbname:   'myapp',
  user:     'jane.doe',
  password: 'secret'
)

# Execute arbitrary SQL
client.execute(sql: 'SELECT version()')
# => { result: [{ version: "PostgreSQL 16.0 ..." }] }

# Parameterized query
client.execute_params(sql: 'SELECT * FROM users WHERE id = $1', params: [42])
# => { result: [{ id: "42", name: "Jane Doe", email: "jane.doe@example.com" }] }

# List tables in a schema
client.list_tables(schema: 'public')
# => { result: ["orders", "products", "users"] }

# Describe a table's columns
client.describe_table(table: 'users')
# => { result: [{ column_name: "id", data_type: "integer", ... }, ...] }

# Total on-disk size of a table (bytes)
client.table_size(table: 'orders')
# => { result: 8192 }

Runner Methods

Queries

Method	Description
execute(sql:)	Run arbitrary SQL, returns rows as array of symbol-keyed hashes
execute_params(sql:, params: [])	Parameterized query with $1, $2 placeholders

Tables

Method	Description
list_tables(schema: 'public')	List table names in the given schema
describe_table(table:, schema: 'public')	Column definitions from information_schema.columns
table_size(table:)	Total relation size in bytes via pg_total_relation_size

Connection Defaults

Option	Default
host	127.0.0.1
port	5432
dbname	postgres
user	postgres
password	nil (omitted if not set)

License

MIT