php - Laravel migration with SQLite -

i have migration in postgres , sqlite, , facing problem sqlite database. same migrations 2 different databases. postgres migration ok, not sqlite. added migration altering table , adding new field.

   public function up()    {        schema::table('retailer_products_photo_fix', function ($table) {             $table->integer('currency_id')->unsigned();            $table                ->foreign('currency_id')                ->references('id')                ->on('currency')                ->onupdate('cascade')                ->ondelete('cascade')            ;             $table->dropcolumn('currency');        });     } 

but following error thrown:

general error: 1 cannot add not null column default value null 

when try add nullable() field isn't created , when add default value 0 or 1 got constraint error because in related table have rows 1 , 2. how can solved?

quoting this answer daniel vassallo:

sqlite doesn't support add constraint variant of alter table command

(the source answer uses here)

so attempting alter table adding foreign key constraint isn't going work. need to:

1. rename table
2. recreate table updated structure (including fk constraint)
3. populate new table existing data, providing values new fields
4. drop old table

you can swap #1 , #2 create temporary version of table, , drop old 1 / rename new 1 @ end, that's you. may safer go route instead in case goes wrong won't have old table in renamed state @ point.