常规错误：1005无法创建表错误：150“外键约束形成错误”）

Blockquote SQLSTATE [HY000]：常规错误：1005无法创建表格gps . ＃sql-9e4_161（错误号码：150“外键约束形成错误”）（SQL：alter table receivers add constraint，receiver_hospital_id_foreign foreign key（hospital_id）references医院（id））

{
    Schema::create('users', function (Blueprint $table) {
        $table->increments('id');
        $table->string('name');
        $table->timestamp('dob');
        $table->string('profile_image');
        $table->string('profession')->nullable();
        $table->string('email')->unique();
        $table->string('weight');
        $table->string('message');
        $table->rememberToken();
        $table->timestamps();
        $table->softDeletes();

    });


{
    Schema::create('receivers', function (Blueprint $table) {
        $table->increments('id');
        $table->integer('member_id')->unsigned()->index();
        $table->integer('hospital_id')->unsigned()->index();
        $table->timestamps();
        $table->softDeletes();
        $table->foreign('member_id')->references('id')->on('members');
        $table->foreign('hospital_id')->references('id')->on('hospitals');
    });


{
    Schema::create('hospitals', function (Blueprint $table) {
        $table->increments('id');
        $table->string('h_name');
        $table->integer('country_id')->unsigned()->index();
        $table->integer('donate_id')->unsigned()->index();
        $table->softDeletes();
        $table->timestamps();
        $table->foreign('country_id')->references('id')->on('countries');
        $table->foreign('donate_id')->references('id')->on('donates');


    });


{
    Schema::create('donates', function (Blueprint $table) {
        $table->increments('id');
        $table->date('date');

        $table->date('last_bleed');
        $table->string('quantity');
        $table->string('comments');
        $table->integer('blood_group_id')->unsigned()->index();
        $table->integer('member_id')->unsigned()->index();

        $table->timestamps();
        $table->softDeletes();
        $table->foreign('blood_group_id')->references('id')-
                             >on('blood_groups');
        $table->foreign('member_id')->references('id')->on('members');
        $table->timestamps();
    });

}