dsync

This is a fork of Wulf's dsync with some Pull Requests merged, see Difference with original

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,
  }).await?;
  
  let todos_list = todos::paginate(&mut db, 1, 10).await?;
  
  let updated_todo = todos::update(&mut db, created_todo.id, UpdateTodo {
    text: created_todo.text,
    completed: true,
  }).await?;
}

For more examples, look into the test/ folder, where in test.sh the options used are listed, schema.rs is the diesel schema and all other files are output from dsync

Library

1. Add this crate:

   cargo add libdsync-hasezoey

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_hasezoey::{GenerationConfig, TableOptions};
   
   pub fn main() {
       let dir = env!("CARGO_MANIFEST_DIR");
   
       dsync_hasezoey::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"

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-hasezoey

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::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)
• --no-serde: (optional) if set, does not output any serde related code
• --model-path: (optional) set a custom model import path, default crate::models::
• --schema-path: (optional) set a custom schema import path, default crate::schema::
• --only-necessary-derives: (optional) set to only generate the base necessary diesel derives for a struct
• --once-common-structs: (optional) if set, common structs like PaginationResult are only generated once
• --single-model-file: (optional) if set, only generate a single table.rs file instead of a table/ directory with mod.rs and generated.rs
• --file-mode: (optional, default overwrite) set which file mode to use
  • overwrite: Overwrite original if exists and has dsync file signature
  • newfile: If changes to the original file would be done, create a .dsyncnew.rs file instead
  • none: Do not change the file and do not create a new file (still lists the file if changes would be done)
• --read-only-prefix: (optional, repeatable) table prefixes to treat as read-only tables (like view_)
• --no-impls: (optional) set to disable generating impl Struct (only generate the structs)
• --lessen-conflicts: (optional) set to lessen conflicts with diesel types
• --create-str: (optional) set to have Create* structs be generated with &'a str instead of String

Notes:

• any other file-mode than newfile will check that the file is a dsync-managed file
• if --once-common-structs is used, then when a table named common is found, a error it thrown
• if --no-impls is used without --once-common-structs, no PaginationResult struct is generated
• if --no-impls and --once-common-structs are used, PaginationResult is generated into common.rs

./test/readme_cli_base_example:

$ dsync -i src/schema.rs -o src/models -c "diesel::SqliteConnection"
Modified models/todos/generated.rs
Modified models/todos/mod.rs
Modified models/mod.rs
Modified 3 files

$ find . -xdev -type f
./src/models/mod.rs
./src/models/todos/mod.rs
./src/models/todos/generated.rs
./src/schema.rs

./test/readme_cli_advanced_example:

$ dsync -i src/schema.rs -o src/models -c "diesel::SqliteConnection" --no-serde --only-necessary-derives --once-common-structs --single-model-file -g updated_at -g created_at
Modified models/todos.rs
Modified models/common.rs
Modified models/mod.rs
Modified 3 files

$ find . -xdev -type f
./src/models/mod.rs
./src/models/todos.rs
./src/models/common.rs
./src/schema.rs

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.

Difference with original

This Fork was made because the original project was not updated anymore since March 2023 and had become incompatible with diesel 2.1.0.

See CHANGELOG.md for all changes since the start of the fork.

FAQ

sqlite get_result DoesNotSupportReturningClause

If you get a error like the following, then the fix is to add feature returning_clauses_for_sqlite_3_35 to the diesel dependency

75   |             .get_result(db)
     |              ---------- ^^ the trait `QueryFragment<Sqlite, DoesNotSupportReturningClause>` is not implemented for `ReturningClause<(sql_schema::media_types::columns::_id, sql_schema::media_types::columns::name)>`
     |              |
     |              required by a bound introduced by this call