sqlstride 0.1.3

Zero-boilerplate schema migrations —straight from your own SQL files.

SQLStride

Zero-boilerplate schema migrations — straight from your own SQL files.

SQLStride is a simple, yet powerful database migration tool that allows you to manage your database schema changes using plain SQL files organized in a specific directory structure.

Installation

pip install sqlstride

Requirements:

• Python 3.8 or higher
• Dependencies: etl-utilities, pymysql, click, pyodbc, pyyaml, jinja2

Configuration

SQLStride uses a YAML configuration file named sqlstride.yaml (for backward compatibility) in your project root directory. Here's an example of what this file should look like:

# Required
sql_dialect: postgres  # Options: postgres, mssql, mariadb
host: localhost

# Optional with no defaults
port: 5432
instance: mssql_db_instance
database: my_database
username: db_user
password: db_password
default_schema: public

# Optional with defaults
trusted_auth: false
log_table: sqlstride_log
lock_table: sqlstride_lock

# Jinja template variables
jinja_vars:
  environment: production
  schema_prefix: app_
  # Add any variables you want to use in your SQL templates

Configuration Options

Option	Description	Default
sql_dialect	SQL dialect to use	postgres
host	Database host (required)	-
port	Database port	-
database	Database name	-
username	Database username	-
password	Database password	-
instance	Instance name (for MSSQL)	-
default_schema	Default schema the log and lock tables will save to	-
trusted_auth	Use trusted authentication (for MSSQL)	false
log_table	Name of the log table	sqlstride_log
lock_table	Name of the lock table	sqlstride_lock
jinja_vars	Variables to use in Jinja SQL templates	{}

Folder Structure and Execution Order

SQLStride executes SQL files in a specific order based on the directory structure. The tool processes directories in the following order:

1. Infrastructure/Runtime

   • extensions (for modules)
   • roles (for users)

2. Namespaces & Custom Types

   • schemas
   • types (domains, enums, composite types)
   • sequences

3. Core Relational Objects

   • tables
   • indexes

4. Reference/Seed Data

   • seed_data (for data)

5. Relational Constraints

   • constraints

6. Programmable Objects

   • functions
   • procedures
   • triggers

7. Wrapper/Presentation Objects

   • views
   • materialized_views
   • synonyms

8. Security & Automation

   • grants (for permissions)
   • jobs (for tasks)

9. Clean-up Scripts

   • retire

Within each directory, SQL files are processed in alphabetical order.

SQL File Format

Each SQL file can contain multiple migration steps. A step is identified by a special comment line:

-- step author:step_id

For example:

-- step john:create_users_table
CREATE TABLE users
(
    id         SERIAL PRIMARY KEY,
    username   VARCHAR(100) NOT NULL,
    email      VARCHAR(255) NOT NULL UNIQUE,
    created_at TIMESTAMP    NOT NULL DEFAULT NOW()
);

-- step john:add_user_index
CREATE INDEX idx_users_username ON users (username);

Jinja Templating

SQLStride supports Jinja2 templating in SQL files. To use this feature, name your SQL files with a .j2 extension ( e.g., users.sql.j2). You can then use Jinja2 syntax in your SQL files:

-- step john:create_users_table
CREATE TABLE {{ schema_prefix }} users
(
    id
    SERIAL
    PRIMARY
    KEY,
    username
    VARCHAR
(
    100
) NOT NULL,
    email VARCHAR
(
    255
) NOT NULL UNIQUE,
    created_at TIMESTAMP NOT NULL DEFAULT NOW
(
)
    );

{% if environment == 'development' %}
-- step john:add_test_user
INSERT INTO {{ schema_prefix }} users (username, email)
VALUES ('test_user', '[e-mail]');
{% endif %}

You can define variables in the jinja_vars section of your configuration file or pass them via the --jinja-vars command-line option as a JSON string.

CLI Usage

Sync Command

The main command is sqlstride sync, which synchronizes your database schema with your SQL files.

sqlstride sync [OPTIONS]

Create Repository Structure

The create_repo command creates the recommended directory structure for your project with blank __init__.py files in each directory. It also interactively prompts you for configuration values to generate a customized configuration file.

sqlstride create_repo [OPTIONS]

Sync Command Options

Option	Description
--project, -p	Path to schema repo containing the configuration file & schema/ (default: current directory)
--host	Database host
--port	Database port
--instance	Instance used for connecting to MSSQL Database
--database, -db	Desired database to connect to on host
--username, -u	Username used for authenticating with the database
--password, -pw	Password used for authenticating with the database
--trusted-auth	Use trusted authentication for connecting to MSSQL Database
--sql-dialect	SQL dialect to use for connecting to database
--default-schema	Schema that the log and lock tables will be created in
--log-table	Name of the table to use to keep track of changes
--lock-table	Name of the table to use to lock the database during sync
--dry-run	Parse & list SQL without executing anything
--same-checksums	Checks the current checksums against the existing checksums and raises an error if they are different
--jinja-vars	JSON string of variables to use in Jinja templates

Create Repository Structure Options

Option	Description
--project, -p	Path to create the repository structure (default: current directory)

Examples

Basic Usage

# Navigate to your project directory containing the configuration file
cd my_project

# Run the sync command
sqlstride sync

# Create the repository structure in the current directory
sqlstride create_repo

Using Command-line Options

# Override configuration options
sqlstride sync --host db.example.com --port 5432 --database my_db --username admin --password secret

# Dry run to see what would be executed without making changes
sqlstride sync --dry-run

# Check if any applied migrations have changed
sqlstride sync --same-checksums

# Create repository structure in a specific directory
sqlstride create_repo --project /path/to/my_new_project

# Use Jinja template variables
sqlstride sync --jinja-vars '{"environment": "development", "schema_prefix": "dev_"}'

Project Structure Example

my_project/
├── sqlstride.yaml  # Configuration file (name kept for backward compatibility)
├── schema/
├── tables/
│   ├── users.sql
│   └── posts.sql.j2  # Jinja template
├── constraints/
│   └── foreign_keys.sql
├── functions/
│   └── user_functions.sql
└── views/
  └── user_posts_view.sql

How It Works

1. SQLStride scans your project directory for SQL files in the specified order.
2. It parses each file to extract migration steps.
3. For files with a .j2 extension, it processes them with Jinja2 templating using the provided variables.
4. It checks which steps have already been applied to the database.
5. It applies any pending steps in the correct order.
6. It records each applied step in the log table with a checksum to ensure idempotency.

This approach allows you to manage your database schema using plain SQL files without having to write boilerplate migration code, with the added flexibility of using templates when needed.