@lebedevna/prettier-plugin-sql

Prettier plugin for formatting a focused subset of PostgreSQL DDL.

The plugin is intentionally narrow. It formats supported statements into the house style shown in example.sql and leaves everything else structurally unchanged.

Install

npm install --save-dev prettier @lebedevna/prettier-plugin-sql

Peer requirement: prettier@^3.

Usage

Prettier config

// prettier.config.js
import sqlPlugin from "@lebedevna/prettier-plugin-sql";

export default {
  plugins: [sqlPlugin],
};

If you use JSON config, reference the package name:

{
  "plugins": ["@lebedevna/prettier-plugin-sql"]
}

Format SQL files

npx prettier --write schema.sql

The plugin registers the sql parser for .sql files.

Example

Input:

create table job(
  job_id integer generated always as identity,
  created_at timestamp not null,
  is_active boolean not null default true,
  constraint status_fk foreign key(status_id) references dict_job_status(id)
) partition by range(created_at)

Output:

CREATE TABLE job (
    job_id     integer   GENERATED ALWAYS AS IDENTITY,
    created_at timestamp NOT NULL,
    is_active  boolean   NOT NULL DEFAULT true,
    CONSTRAINT status_fk FOREIGN KEY (status_id) REFERENCES dict_job_status (id)
) PARTITION BY RANGE (created_at);

Supported Statements

• CREATE DOMAIN ... AS ...
• CREATE TYPE ... AS ENUM (...)
• CREATE TABLE ...

Supported Table Formatting

For supported CREATE TABLE statements, the formatter currently handles:

• column definitions
• quoted identifiers
• table constraints such as PRIMARY KEY, UNIQUE, and FOREIGN KEY ... REFERENCES ...
• GENERATED ALWAYS AS IDENTITY
• DEFAULT ...
• explicit NULL and NOT NULL
• inline -- comments placed above columns or constraints
• PARTITION BY RANGE (...)

Behavior

• Uppercases supported structural keywords while preserving identifier case and string literals
• Aligns column names, data types, and nullability within a table
• Reorders nullability ahead of trailing clauses such as DEFAULT
• Preserves unsupported statements instead of trying to restyle them
• Normalizes the final output to include a trailing semicolon and newline
• Throws on invalid PostgreSQL syntax instead of guessing

Unsupported SQL

Unsupported SQL is passed through with minimal normalization. For example, a SELECT statement is kept as-is apart from trailing semicolon cleanup.

This makes the plugin safe to use on mixed files only if you are comfortable with supported PostgreSQL DDL being reformatted while unsupported SQL mostly stays in its original layout.

Limitations

• This is not a general-purpose SQL formatter
• The scope is PostgreSQL-oriented DDL, not multi-dialect SQL
• CREATE TABLE support is limited to tables the parser can map into the plugin's supported entry model
• There are currently no plugin-specific options

Development

npm test