remodel-core

remodel-core is a Rust library for database modeling. It lets you build conceptual ER models, convert them into logical relational schemas, and render SQL DDL for supported dialects.

This crate is a Rust reimplementation of the core modeling engine from brModelo by Carlos Henrique Candido and contributors. The port keeps the same GPL-3.0-or-later licensing model.

What it provides

• Conceptual modeling primitives: entities, attributes, relationships, cardinalities, specializations, unions, and associative entities.
• Logical modeling primitives: tables, columns, primary keys, unique constraints, and foreign keys.
• Conceptual-to-logical transformation with configurable strategies for relationships, specializations, and complex attributes.
• SQL DDL rendering for PostgreSQL, MySQL, and SQLite.
• Validation diagnostics for structurally invalid diagrams.
• serde support for persistence and interchange formats.

Installation

cargo add remodel-core

Quick start

use remodel_core::models::conceptual::AttributeOwner;
use remodel_core::prelude::*;

fn main() -> Result<()> {
    let mut model = ConceptualModel::new("library");

    let book = model.add_entity("Book");
    model.add_primary_attribute(book, "id", DataType::Integer)?;
    model.add_attribute(
        AttributeOwner::Entity(book),
        "title",
        DataType::Varchar(255),
    )?;

    let author = model.add_entity("Author");
    model.add_primary_attribute(author, "id", DataType::Integer)?;
    model.add_attribute(
        AttributeOwner::Entity(author),
        "name",
        DataType::Varchar(120),
    )?;

    model
        .relate("wrote", book, Cardinality::ZeroToMany)
        .with(author, Cardinality::OneToMany)
        .id();

    let logical = model.to_logical()?;
    let sql = logical.to_sql(SqlDialect::Postgres);

    println!("{sql}");
    Ok(())
}

This produces a relational model with Book, Author, and a junction table for wrote.

Modeling pipeline

remodel-core follows the usual database-design flow:

1. Build a conceptual model.
2. Validate and convert it into a logical model.
3. Render SQL DDL for the target database dialect.

The main APIs are:

• ConceptualModel for ER authoring
• ConceptualModel::to_logical() for default conversion
• transform::conceptual_to_logical() when you need custom ConvertOptions
• LogicalModel::to_sql() for final DDL generation

Supported SQL dialects

• PostgreSQL
• MySQL / MariaDB
• SQLite

Validation

The library validates conceptual models before conversion. Structural problems such as missing references or invalid identifiers are reported through diagnostics, and conversion returns Error::Validation when errors are present.

Release

Publishing to crates.io is automated through GitHub Actions:

• Push a tag named remodel-core-vX.Y.Z, or
• Run the Publish remodel-core workflow manually.

The workflow runs the crate tests and then publishes RemodelCore/ using the repository secret CARGO_REGISTRY_TOKEN.

License

GPL-3.0-or-later.