规则第四：独特laravel验证参数

通过laravel文档看看，API文档和源代码，我想知道如果任何人知道有什么第四参数id在下面的唯一规则是？

'email' => 'unique:users,email_address,NULL,id,account_id,1'

我现在理解这个规则：

• users看这个表
• email_address检查对本栏目
• NULL可能我们可以忽略一个主键/ ID值，但我们也没因此此参数被忽略
• id—不确定
• account_id-额外的WHERE子句，这是栏目名称
• 1- The value for_帐户ID在WHERE子句中

文件：http：／／laravel.com /文档/ 4.2验证

功能负责实施中发现的独特的规则验证\Illuminate\Validation\Validator在功能validateunique（美元美元美元价值，属性，参数）对线949：

/**
 * Validate the uniqueness of an attribute value on a given database table.
 *
 * If a database column is not specified, the attribute will be used.
 *
 * @param  string  $attribute
 * @param  mixed   $value
 * @param  array   $parameters
 * @return bool
 */
protected function validateUnique($attribute, $value, $parameters)
{
    $this->requireParameterCount(1, $parameters, 'unique');

    $table = $parameters[0];

    // The second parameter position holds the name of the column that needs to
    // be verified as unique. If this parameter isn't specified we will just
    // assume that this column to be verified shares the attribute's name.
    $column = isset($parameters[1]) ? $parameters[1] : $attribute;

    list($idColumn, $id) = array(null, null);

    if (isset($parameters[2]))
    {
        list($idColumn, $id) = $this->getUniqueIds($parameters);

        if (strtolower($id) == 'null') $id = null;
    }

    // The presence verifier is responsible for counting rows within this store
    // mechanism which might be a relational database or any other permanent
    // data store like Redis, etc. We will use it to determine uniqueness.
    $verifier = $this->getPresenceVerifier();

    $extra = $this->getUniqueExtra($parameters);

    return $verifier->getCount(

        $table, $column, $value, $id, $idColumn, $extra

    ) == 0;
}

干杯