declare-schema

Experiments with Rust declarative schemas

Use sqlparser-rs for SQL -> AST, then diff ASTs to generate ALTER ASTs, then output SQL.

WARNING: Alpha software, you will likely lose data with this library.

Goal

In application

Include database schema management in to Rust applications without the need for migration steps.

As a CLI

Provide a CLI tool that can generate diffs of schemas and the required ALTER statements for review to detect schema drift.

Easy development experience

When embedded in an application or with a CLI tool keep an easy SQL -> DB flow that is clear to developers with an easy to modify schema.

Current State

Limitations

CREATE EXTENSION - Can be created by name only. Cannot be DROPed.

CONSTRAINT - Cannot be changed, create a new one then drop the old one.

CREATE INDEX - Indexes cannot be ALTERed. To avoid errors in change detection/halting

• Specify the schema name for the table when creating the index
• Specify the method for USING that matches defaults:

example: CREATE INDEX idx_id on public.test USING BTREE (id DESC)