Laravel migrations

1. Migration Basics

Create a Migration

php artisan make:migration create_table_name_table

Example:

php artisan make:migration create_users_table

Run Migrations

Run all pending migrations:

php artisan migrate

Rollback Migrations

Rollback the most recent batch of migrations:

php artisan migrate:rollback

Rollback & Re-run Migrations

Rollback and re-run all migrations:

php artisan migrate:refresh

Reset Migrations

Rollback all migrations completely:

php artisan migrate:reset

Run Specific Migration

Run a single migration file:

php artisan migrate --path=/database/migrations/filename.php

Status of Migrations

Check migration status (applied or pending):

php artisan migrate:status

---

2. Table Operations

Create a Table

To create a table, use:

Schema::create('table_name', function (Blueprint $table) {
    $table->id();
    $table->string('name');
    $table->timestamps();
});

Modify an Existing Table

To modify an existing table, you need to create a new migration:

php artisan make:migration add_columns_to_table_name_table

---

3. Adding Columns

Add a New Column

Schema::table('table_name', function (Blueprint $table) {
    $table->string('new_column');
});

Add Multiple Columns

Schema::table('table_name', function (Blueprint $table) {
    $table->integer('age');
    $table->string('address')->nullable();
});

Add Column with Default Value

Schema::table('table_name', function (Blueprint $table) {
    $table->boolean('status')->default(1);
});

---

4. Dropping Columns

Drop a Single Column

Schema::table('table_name', function (Blueprint $table) {
    $table->dropColumn('column_name');
});

Drop Multiple Columns

Schema::table('table_name', function (Blueprint $table) {
    $table->dropColumn(['column1', 'column2']);
});

---

5. Rename Operations

Rename a Column

Schema::table('table_name', function (Blueprint $table) {
    $table->renameColumn('old_name', 'new_name');
});

Rename a Table

Schema::rename('old_table_name', 'new_table_name');

---

6. Altering Columns

Change Column Type

Install the doctrine/dbal package:

composer require doctrine/dbal

Then use:

Schema::table('table_name', function (Blueprint $table) {
    $table->string('column_name')->change();
});

Make Column Nullable

Schema::table('table_name', function (Blueprint $table) {
    $table->string('column_name')->nullable()->change();
});

---

7. Indexing

Add an Index

$table->index('column_name');

Add a Unique Index

$table->unique('column_name');

Add a Composite Index

$table->index(['column1', 'column2']);

Drop an Index

$table->dropIndex('index_name');

Drop a Unique Index

$table->dropUnique('table_name_column_name_unique');

---

8. Foreign Keys

Add Foreign Key

Schema::table('table_name', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');
    $table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
});

Drop Foreign Key

$table->dropForeign('table_name_user_id_foreign');

---

9. Timestamps and Soft Deletes

Add Timestamps

$table->timestamps();

Add Soft Deletes

$table->softDeletes();

Drop Soft Deletes

$table->dropSoftDeletes();

---

10. Miscellaneous

Add Remember Token

$table->rememberToken();

Add UUID as Primary Key

$table->uuid('id')->primary();

Check Table Existence

if (!Schema::hasTable('table_name')) {
    Schema::create('table_name', function (Blueprint $table) {
        $table->id();
    });
}

Check Column Existence

if (!Schema::hasColumn('table_name', 'column_name')) {
    Schema::table('table_name', function (Blueprint $table) {
        $table->string('column_name');
    });
}

---

11. Migration Rollbacks with Specific Steps

Rollback Last 'N' Migrations

Rollback a specific number of migrations:

php artisan migrate:rollback --step=2

Rollback and Re-run Specific Steps

php artisan migrate:refresh --step=2

---

12. Running Migrations in Production

To force migration in production without a prompt:

php artisan migrate --force

---

Practice Tips

1. Practice table creation with all column types (string, integer, boolean, json, text, etc.).
2. Simulate database changes using rollback, refresh, and reset.
3. Implement foreign key constraints with cascading deletes.
4. Work on adding soft deletes and testing data recovery.
5. Try renaming columns and tables using migration.