Database Migration

Database migration is a process that allows you to manage your database schema changes in a structured and version-controlled way. It tracks the migrations that have already been run, making it a crucial part of database management. Luminova provides built-in support for database migrations through the novakit command line tool, making it easier to track, versions and apply changes to the database schema.

How Migration Works

1. Version Control: Migration backups and lock files are stored in your project's writable directory. Each migration file contains a timestamp, ensuring a unique and ordered application of schema changes.

2. Up, Down, and Alter Methods: Migration files in Luminova typically include three methods: up, down, and optional alter.

   • The up method applies changes to the database schema (e.g., creating tables, adding columns).
   • The down method reverts the changes made by the up or modify method (e.g., dropping tables), allowing for rollback if needed.
   • The modify method is an additional method introduced by Luminova. It allows for altering existing database tables without fully migrating them again, providing flexibility for incremental changes.

These methods ensure that database schema changes can be applied and reverted in a controlled manner, maintaining database integrity across different stages of development and deployment.

3. Migration Setup: Create a class that extends \Luminova\Database\Migration. Ensure all migration classes are placed in the /app/Database/Migrations/ directory for proper execution.

4. Migration Management: Luminova provides novakit commands to create, apply, and rollback migrations. These commands ensure that migrations are executed in the correct order and only once.

• Class namespace: \Luminova\Database\Migration
• This class is an Abstract class

Methods

To get started to documentation reference for Database Table Schema.

up

Defines the database table schema for migrations.

public abstract up(): void

Up Examples

Define your database table schema within the up method.

<?php
public function up(): void
{
  Schema::create('users', static function (Table $table): Table {
    $table->id();
    $table->string('name')->nullable(false);
    $table->string('phone')->nullable(false)->unique();
    $table->string('email')->nullable(false)->unique();
    $table->timestamps();

    return $table;
  });
}

down

Defines the migration reversion.

public abstract down(): void

Down Examples

Drop a table during rollback or migration within the down method.

<?php
public function down(): void
{
  Schema::dropIfExists('users');
}

Or use the drop method.

<?php
public function down(): void
{
  Schema::drop('users');
}

alter

Defines the database table schema modifications to alter columns or tables.

The alter method is particularly useful for making targeted changes to database tables mostly in production environments. Unlike migrating an entire table and reseeding, alter allows you to apply specific alterations efficiently.

The alter method will create a lock version only if the current migration class isn't already locked. Otherwise, it executes the alteration without changing the latest version code.

It's crucial to use the --drop-columns flag with caution. This option drops any previous columns that do not exist in the new altering columns, potentially affecting data integrity.

public alter(): void

Alter Examples

Define your database table or column schema modifiers within the alter method:This example will add a VARCHAR column with country as the name, NULLABLE and default value Nigeria.

<?php
public function alter(): void
{
    Schema::modify('users', static function (Table $table): Table {
        $table->string('country')->nullable()->default('Nigeria');
        return $table;
    });
}

To rename database table, call rename method within the alter method:

<?php
public function alter(): void
{
    Schema::rename('users', 'new-users');
}

invoke

Invoke another migration class within the current migration up or down method.

final protected invoke(class-string<\Luminova\Database\Migration> $migrate): void

Parameters:

Note:If you specify other migration class using invoke method, it will also be executed while running drop, up or rollback migration.

Command Usages

To executes database table migrations, applying the necessary changes to your database schema. These commands helps manage and apply schema changes in a version-controlled manner, ensuring consistency and ease of migration rollback if needed.

Migration Commands

To execute all pending migrations.

php novakit db:migrate

To execute a specific migration class.

php novakit db:migrate --class=TestMigration

To reverse changes and rollback to earlier version, you need to specify the migration class and use rollback flag.

php novakit db:migrate --class=TestMigration --rollback

Drop Command

You can also use the db:drop command to drop migrations, which is equivalent to executing php novakit db:migrate --drop. You can specify the --no-backup flag to skip creating a backup.

Drop all migrations table.

php novakit db:drop

Drop a specific migration class table.

php novakit db:drop --class=TestMigration

Migration Command Options

• -c, --class

  • Description: Specify the migration class to run.
  • Usage: php novakit db:migrate --class=TestMigration

• -n, --no-backup

  • Description: Run migration without creating a backup. This option is useful for speeding up the process but should be used with caution.
  • Usage: php novakit db:migrate --no-backup

• -d, --drop

  • Description: Drop the table by calling the down method during migration. This option helps in cleaning up old or deprecated tables.
  • Usage: php novakit db:migrate --drop

• -r, --rollback

  • Description: Rollback the migration to the previous version. This is helpful for reverting changes that were applied by mistake or need adjustments.
  • Usage: php novakit db:migrate --rollback

• -b, --debug

  • Description: Display SQL query string that was complied to execute in migration.
  • Usage: php novakit db:migrate --debug

• -i, --invoke

  • Description: Run migration and also invoke other invokable migration classes.
  • Usage: php novakit db:migrate --invoke

Alter Commands

Execute pending database table alterations.

php novakit db:alter

Execute alterations for a specific migration class.

php novakit db:alter --class=TestMigration

Alter Command Options

• -c, --class

  • Description: Specify the migration class for alteration.
  • Example: php novakit db:alter --class=TestMigration

• -n, --no-backup

  • Description: Execute alteration without creating a backup. Useful for speeding up the process.
  • Example: php novakit db:alter --no-backup

• -d, --drop-columns

  • Description: Drop previous columns not present in the new alteration.
  • Example: php novakit db:alter --drop-columns

• -b, --debug

  • Description: Display SQL query string that was complied to execute in migration alteration.
  • Usage: php novakit db:alter --debug

Schema Methods

These methods can be called within the up, down, or alter methods of your migration class.

• Full name: \Luminova\Database\Schema
• Final Class: This class is marked as final and cannot be subclassed.

create

Creates a new table using a callback function to build the table schema.

public static create(string $tableName, \Closure $tableCallback): void

Parameters:

Throws:

• \Luminova\Exceptions\DatabaseException - If any error occurred.

The Closure table callback function must return an instance of \Luminova\Database\Table.

Your callback function must must type-hint \Luminova\Database\Table which will be injected during migration execution.

modify

Alters a table and its columns using a callback function to modify the table schema.This is should be called within the alter method of your migration class.

public static modify(string $tableName, \Closure $tableCallback): void

Parameters:

Throws:

• \Luminova\Exceptions\DatabaseException - If any error occurred.

The Closure table callback function must return an instance of \Luminova\Database\Table.

Your callback function must must type-hint \Luminova\Database\Table which will be injected during migration alteration execution.

rename

Alter rename a table in the specified database.This is should be called within the alter method of your migration class.

public static rename(string $from, string $to, string $database = 'mysql'): void

Parameters:

Throws:

• \Luminova\Exceptions\DatabaseException - If any error occurred.

dropIfExists

Drops a table if it exists.This is should be called within the down method of your migration class.

public static dropIfExists(string $tableName): void

Parameters:

drop

Drops a table.This is should be called within the down method of your migration class.

public static drop(string $tableName): void

Parameters: