add README

README.md

@@ -1 +1,136 @@
-# atlas-provider-sqlalchemy
+# atlas-provider-sqlalchemy
+
+Load [SQLAlchemy](https://www.sqlalchemy.org/) models into an [Atlas](https://atlasgo.io) project.
+
+### Use-cases
+1. **Declarative migrations** - use a Terraform-like `atlas schema apply --env sqlalchemy` to apply your SQLAlchemy schema to the database.
+2. **Automatic migration planning** - use `atlas migrate diff --env sqlalchemy` to automatically plan a migration from the current database version to the SQLAlchemy schema.
+
+### Installation
+
+Install Atlas from macOS or Linux by running:
+```bash
+curl -sSf https://atlasgo.sh | sh
+```
+
+See [atlasgo.io](https://atlasgo.io/getting-started#installation) for more installation options.
+
+Install the provider by running:
+```bash
+pip install atlas-provider-sqlalchemy
+```
+
+#### Standalone 
+
+If all of your SQLAlchemy models exist in a single package, 
+you can use the provider directly to load your SQLAlchemy schema into Atlas.
+
+In your project directory, create a new file named `atlas.hcl` with the following contents:
+
+```hcl
+data "external_schema" "sqlalchemy" {
+  program = [
+    "atlas-provider-sqlalchemy",
+    "--path", "./path/to/models",
+    "--dialect", "mysql" // mariadb | postgresql | sqlite | mssql
+  ]
+}
+
+env "sqlalchemy" {
+  src = data.external_schema.sqlalchemy.url
+  dev = "docker://mysql/8/dev"
+  migration {
+    dir = "file://migrations"
+  }
+  format {
+    migrate {
+      diff = "{{ sql . \"  \" }}"
+    }
+  }
+}
+```
+
+#### As Python Script 
+
+If you want to use the provider as a python script, you can use the provider as follows:
+
+Create a new file named `load_models.py` with the following contents:
+
+```python
+# import all models
+from models import User, Task
+from atlas_provider_sqlalchemy.ddl import print_ddl
+print_ddl("mysql", [User, Task])
+```
+
+Next, in your project directory, create a new file named `atlas.hcl` with the following contents:
+
+```hcl
+data "external_schema" "sqlalchemy" {
+    program = [
+        "python",
+        "load_models.py"
+    ]
+}
+
+env "sqlalchemy" {
+  src = data.external_schema.sqlalchemy.url
+  dev = "docker://mysql/8/dev"
+  migration {
+    dir = "file://migrations"
+  }
+  format {
+    migrate {
+      diff = "{{ sql . \"  \" }}"
+    }
+  }
+}
+```
+
+### Usage
+
+Once you have the provider installed, you can use it to apply your SQLAlchemy schema to the database:
+
+#### Apply
+
+You can use the `atlas schema apply` command to plan and apply a migration of your database to your current SQLAlchemy schema.
+This works by inspecting the target database and comparing it to the SQLAlchemy schema and creating a migration plan.
+Atlas will prompt you to confirm the migration plan before applying it to the database.
+
+```bash
+atlas schema apply --env sqlalchemy -u "mysql://root:password@localhost:3306/mydb"
+```
+Where the `-u` flag accepts the [URL](https://atlasgo.io/concepts/url) to the
+target database.
+
+#### Diff
+
+Atlas supports a [version migration](https://atlasgo.io/concepts/declarative-vs-versioned#versioned-migrations) 
+workflow, where each change to the database is versioned and recorded in a migration file. You can use the
+`atlas migrate diff` command to automatically generate a migration file that will migrate the database
+from its latest revision to the current Sequelize schema.
+
+```bash
+atlas migrate diff --env sqlalchemy 
+````
+
+### Supported Databases
+
+The provider supports the following databases:
+* MySQL
+* MariaDB
+* PostgreSQL
+* SQLite
+* Microsoft SQL Server
+
+### Credit
+
+The code in this repository is based on [noamtamir/atlas-provider-sqlalchemy](https://github.com/noamtamir/atlas-provider-sqlalchemy).
+
+### Issues
+
+Please report any issues or feature requests in the [ariga/atlas](https://github.com/ariga/atlas/issues) repository.
+
+### License
+
+This project is licensed under the [Apache License 2.0](LICENSE).