Large Auto Increment IDs

问题

I'm having a strange issue with some auto-inc IDs on a table, where instead of going up by 1 each time, it seems to be going up by 10 each time.

I'm using the

ClearDB MySQL Addon for Heroku
PHP 5.5.15
Apache 2.4.10
Laravel dev branch (4.something)

I've created the database via artisan's migrate functionality, My migration for the database table is

<?php

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateCheckinTable extends Migration {

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('checkins', function(Blueprint $table)
        {
            $table->increments('id');

            $table->integer('visitor_id');
            $table->integer('meeting_id');

            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('checkins');
    }

}

However when Im creating a new entry via this

    $this->checkin = new Checkin;
    $this->checkin->visitor_id = $this->id;
    $this->checkin->meeting_id = $this->nextMeetingId();
    $this->checkin->save();

The Checkin Class looks like

<?php

class Checkin extends Eloquent {

    /**
     * The database table used by the model.
     *
     * @var string
     */
    protected $table = 'checkins';

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = array('updated_at', 'visitor_id');

    protected $fillable = array();

    public function meeting(){
        return $this->hasOne('Meeting','id', 'meeting_id');
    }

    public function client(){
        return $this->hasOne('Visitor','id','visitor_id');
    }

}

However after F5ing and adding multiple entries the database table now looks like

id  visitor_id meeting_id updated_at created_at

1   1   0   2014-08-04 21:25:25 2014-08-04 21:25:25
11  1   0   2014-08-04 21:35:54 2014-08-04 21:35:54
21  1   0   2014-08-04 21:35:57 2014-08-04 21:35:57
31  1   0   2014-08-04 21:35:59 2014-08-04 21:35:59
41  1   0   2014-08-04 21:36:01 2014-08-04 21:36:01
51  1   0   2014-08-04 21:36:03 2014-08-04 21:36:03

As you can see the id's is going up by 10 each time rather than 1.

So if anybody knows the reason for this, please update me :)

Many thanks

回答1:

As an answer for others experiencing this issue.

The reason for the big steps was due to a MySQL Configuration that ClearDB had implimented.

Their reasoning for doing this is listed here: http://www.cleardb.com/developers/help/faq#general_16 (Thanks Razor for this)

If you need to investigate your increment settings yourself you can run the following query

SHOW VARIABLES LIKE 'auto_inc%';

this will output something like

auto_increment_increment    10
auto_increment_offset   1

So you can see the reason for my jumps was because this was set to 10.

As @Juergen d said you should be able to change this if you need to by the following queries.

SET @@auto_increment_increment=1
SET GLOBAL auto_increment_increment=1;

I however didnt change this setting as ClearDB set it for a reason, and I was only querying this incase it was something i had mis-configured.

Case Closed, Thanks to everybody for their input.

来源：https://stackoverflow.com/questions/25127226/large-auto-increment-ids

标签

php

mysql

laravel

auto-increment