php artisan make:migration rebuild_foreign_keys_with_on_delete_cascade_on_update_cascade

<?php


use IlluminateSupportFacadesSchema;
use IlluminateDatabaseSchemaBlueprint;
use IlluminateDatabaseMigrationsMigration;
class RebuildForeignKeysWithOnDeleteCascadeOnUpdateCascade extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        // We connect to the DB and we call DoctrineSchemaManager to perform the magic for us.
        $con = Schema::getConnection()->getDoctrineSchemaManager();
        // Here we retrieve all the database table names
        $tb_names = $con->listTableNames();
        // Now we start to retrieve all the foreign key for each table
        foreach ($tb_names as $tb_name){
            // Here the table name will be used in the function that laravel docs indicate to modify columns and other table attributes.
            Schema::table($tb_name, function (Blueprint $table) use ($tb_name, $con){
                // Here we retrieve all foreign keys from this specific table
                $foreignKeys = $con->listTableForeignKeys($tb_name);
                // First of all we obviously check if its empty in order to evaluate if it should be executed or not.
                if (count($foreignKeys))
                {
                    /* Once inside, we make sure that there are not foreign keys and we proceed to the update from ON DELETE NO ACTION to ON DELETE CASCADE
We loop key by key */
                    foreach ($foreignKeys as $foreignKey)
                    {
                        // Here we retrieve the local column, that means the column that saved the id of the foreign key relationship.
                        $local_col = $foreignKey->getLocalColumns()[0];
                        // Here we retrieve the name of our foreign table
                        $foreign_table = $foreignKey->getForeignTableName();
                        // Here we retrieve our foreign key column
                        $foreign_col = $foreignKey->getForeignColumns()[0];
                        // Here we retrieve the foreign key name
                        $fk_name = $foreignKey->getName();
                        /* Now we proceed to break the foreign relationship, which is the proper way to rebuild a foreign key relationship.*/
                        $table->dropForeign($fk_name);
                        /* Once the foreign key relationship has been broken , we rebuild it  taking into account that new events should be  ON DELETE and ON UPDATE CASCADE */
                        $table
                            ->foreign($local_col, $fk_name)
                            ->references($foreign_col)
                            ->on($foreign_table)
                            ->onUpdate('CASCADE')
                            ->onDelete('CASCADE');
                    }
                }
            });
        }
    }


    /**
     * Reverse the migrations.
     *
     * @return void
     */


    /* The rollback migration function should be almost the same with only one differente which is to switch back the foreign key relationship to ON DELETE NO ACTION AND ON UPDATE NO ACTION.*/
    public function down()
    {
        $con = Schema::getConnection()->getDoctrineSchemaManager();
        $tb_names = $con->listTableNames();
        foreach ($tb_names as $tb_name)
        {
            Schema::table($tb_name, function (Blueprint $table) use ($tb_name, $con)
            {
                $foreignKeys = $con->listTableForeignKeys($tb_name);
                if (count($foreignKeys))
                {
                    foreach ($foreignKeys as $foreignKey)
                    {
                        $local_col = $foreignKey->getLocalColumns()[0];
                        $foreign_table = $foreignKey->getForeignTableName();
                        $foreign_col = $foreignKey->getForeignColumns()[0];
                        $fk_name = $foreignKey->getName();
                        $table->dropForeign($fk_name);
                        $table
                            ->foreign($local_col, $fk_name)
                            ->references($foreign_col)
                            ->on($foreign_table)
                            ->onUpdate('NO ACTION')
                            ->onDelete('NO ACTION');
                    }
                }
            });
        }
    }
}