# declare-schema
Experiments with Rust declarative schemas
Use [sqlparser-rs](https://github.com/sqlparser-rs/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 `DROP`ed.
`CONSTRAINT` - Cannot be changed, create a new one then drop the old one.
`CREATE INDEX` - Indexes cannot be `ALTER`ed. 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)`