Question

<?php
// Model
class ProfileDelivery extends \Eloquent {
    protected $table = 'profile_delivery';
    protected $guarded = array();
    public $timestamps = FALSE;
}

// Somewhere
$deliveryGuy->id = 1;
print $deliveryGuy->id; // Prints 1
if (!$deliveryGuy->save()) {
    throw new \Exception('Cant save .');
}
print $deliveryGuy->id; // Prints 0

任何人都可以解释为什么ID值会丢失吗？

Answer 1

不确定你是否为你的情况解决了这个问题，但在Laravel 5.1中这恰好发生在我身上 - 一个表的主键与另一个表的主键相同，因为存在0或1对1的关系他们之间。

发生的事情是Eloquent将主键分配给插入的最后一个插入ID，但由于主键不是自动增量值，因此将其分配给零。它正确存储在数据库中，但如果需要使用该密钥，则保存后的模型无用。解决方案是覆盖具有外部主键的模型的insertAndSetId函数，以防止其设置主键属性。当然，对于做具有自动递增键的任何模型，您不希望这样做，只是您手动分配主键的模型。如果您在创建模型后不需要立即使用该模型也没有必要，因为正如我上面所述，数据库中包含正确的信息。

protected function insertAndSetId(Builder $query, $attributes)
{
    $id = $query->insertGetId($attributes, $keyName = $this->getKeyName());

    // $this->setAttribute($keyName, $id);
}

Answer 2

这是因为数据库中的id列可能没有设置自动增量。

我尝试使用没有自动增量的测试模型并返回0，但是当我将id列更改为autoincrement时，它正确地返回了id。

在laravel / Framework / Src / Illuminate / Database / Eloquent / Model.php中检查此功能

它表示如果它有自动增量，它将插入并设置id。

protected function performInsert($query)
    {
        if ($this->fireModelEvent('creating') === false) return false;

        // First we'll need to create a fresh query instance and touch the creation and
        // update timestamps on this model, which are maintained by us for developer
        // convenience. After, we will just continue saving these model instances.
        if ($this->timestamps)
        {
            $this->updateTimestamps();
        }

        // If the model has an incrementing key, we can use the "insertGetId" method on
        // the query builder, which will give us back the final inserted ID for this
        // table from the database. Not all tables have to be incrementing though.
        $attributes = $this->attributes;

        if ($this->incrementing)
        {
            $this->insertAndSetId($query, $attributes);
        }

        // If the table is not incrementing we'll simply insert this attributes as they
        // are, as this attributes arrays must contain an "id" column already placed
        // there by the developer as the manually determined key for these models.
        else
        {
            $query->insert($attributes);
        }

        // We will go ahead and set the exists property to true, so that it is set when
        // the created event is fired, just in case the developer tries to update it
        // during the event. This will allow them to do so and run an update here.
        $this->exists = true;

        $this->fireModelEvent('created', false);

        return true;
    }

Answer 3

对我来说，我必须将保护$ primaryKey设置为模型中主键的列名来解决问题。（skill_id是列名，因此在Skill模型中我设置了protected $ primaryKey ='skill_id'，默认为'id'。）

插入后Laravel4 Model主键值丢失

3 个答案: