anthonymichaeltdm/dsync

Generate rust structs & query functions from diesel schema files

dsync

A utility to generate database structs and querying code from diesel schema files. Primarily built for create-rust-app.

Currently, it's more advantageous to generate code over deriving code with macros because intellisense and autocompletion isn't quite there when it comes to macro expansion.

Demo

Given the following schema:

// schema.rs
diesel::table! {
    todos (id) {
        id -> Int4,
        text -> Text,
        completed -> Bool,
    }
}

We run:

cargo dsync -i schema.rs -o models

Now we have everything we need!

use models::todos;

async fn demo(db: Connection) {
  let created_todo = todos::create(&mut db, todos::CreateTodo {
    text: "Create a demo",
    completed: false,
  })?;
    
  let updated_todo = todos::update(&mut db, created_todo.id, UpdateTodo {
    text: created_todo.text,
    completed: true,
  })?;
}

For a complete example, see test/simple_table/schema.rs which generates all the code in test/simple_schema/models.

Usage

1. Add this crate:

   cargo add dsync

2. Create a new binary in your project which uses the crate (for example, bin/dsync.rs)

   use std::{collections::HashMap, path::PathBuf};
   use dsync::{GenerationConfig, TableOptions};
   
   pub fn main() {
       let dir = env!("CARGO_MANIFEST_DIR");
   
       dsync::generate_files(
           PathBuf::from_iter([dir, "src/schema.rs"]), 
           PathBuf::from_iter([dir, "src/models"]), 
           GenerationConfig { /* ... your generation options ... */ }
       );
   }

3. Create a Cargo.toml binary entry:

   [[bin]]
   name = "dsync"
   path = "bin/dsync.rs"

4. Execute!

   cargo run --bin dsync

Protip: to use cargo dsync, create an alias in .cargo/config:

[alias]
dsync="run --bin dsync"

Pre-built binary

Setting up a custom binary allows you to completely customize the generation; however, if complete customization isn't necessary, you can install the CLI directly (you'll have to make sure you keep it up-to-date by running this periodically):

cargo install dsync 

CLI Usage

• -i: input argument: path to schema file
• -o: output argument: path to directory where generated code should be written
• -c: connection type (for example: diesel::r2d2::PooledConnection<diesel::r2d2::ConnectionManager<diesel::pg::PgConnection>>)
• -g: (optional, repeatable) list of columns that are automatically generated by create/update triggers (for example, created_at, updated_at)
• --tsync: (optional) adds #[tsync] attribute to generated structs (see https://github.com/Wulf/tsync)
• --model-path: (optional) set a custom model import path, default crate::models::
• --schema-path: (optional) set a custom schema import path, default crate::schema::
• --no-serde: (optional) if set, does not output any serde related code
• --no-crud: (optional) Do not generate the CRUD functions for generated models
• --create-str: (optional) Set which string type to use for Create* structs (possible are string, str, cow)
• --update-str: (optional) Set which string type to use for Update* structs (possible are string, str, cow)
• --single-model-file: (optional) Generate only a single model file, instead of a directory with mod.rs and generated.rs
• --readonly-prefix: (optional, repeatable) A prefix to treat a table matching this as readonly *2
• --readonly-suffix: (optional, repeatable) A suffix to treat a table matching this as readonly *2
• --diesel-backend: (when the "advanced-queries" feature is enabled) The diesel backend in use (possible values include diesel::pg::Pg, diesel::sqlite::Sqlite, diesel::mysql::Mysql, or your custom backend type)
• note: the CLI has fail-safes to prevent accidental file overwriting

dsync -i src/schema.rs -o src/models

Notes:

• *2: "readonly" tables dont have Update* & Create* structs, only *(no suffix / prefix) structs. For example this is useful for Sqlite views, which are read-only (cannot be written to, but can be read)

Experimental API

We're currently experimenting with advanced query generation. This includes pagination, filtering/searching, and the like. Enable the advanced-queries feature flag to see some of it in action.

Alternatively, you can see what gets generated in the advanced queries test here: test/advanced_queries/models

Feel free to open an issue to discuss these API and provide your feeedback.

Docs

See dsync --help for more information.

Feel free to open tickets for support or feature requests.

Development/Testing

Use ./test/test_all.sh to run tests. After running the test, there should be no unexpected changes to files in ./test (use git status and git diff to see if there were any changes).

License

This tool is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.