Framework: Validate unique field with where clause and null value

[set0x]

• Laravel Version: 5.6.23
• PHP Version: PHP 7.2.4 (cli) (built: Mar 28 2018 04:27:01) ( ZTS MSVC15 (Visual C++ 2017) x64 )
• Database Driver & Version: MYSQL 5.7.21

Description:

When you use unique validation rule with "where" clause and a"null" value cause an error in laravel\framework\src\Illuminate\Validation\Concerns\ValidatesAttributes.php in getExtraConditions
because the 'null' value is deleted from array $segments

Steps To Reproduce:

Rules to validate.

return [
    'name' => Rule::unique('lodgings')->where('type_id', $this->type),
    'type' => 'required',
];

When not pass type_id attribute cause a error.

But this, work.

return [
    'name' => Rule::unique('lodgings')->where('type_id', $this->type ?? 'null'),
    'type' => 'required',
];

[set0x]

I don't know which is the better solution...

If the value is null, do not add the condition where

https://github.com/laravel/framework/blob/a784efcc17b1c683bb64b6e0916c4e2a6cea231c/src/Illuminate/Validation/Rules/DatabaseRule.php#L57

//framework\src\Illuminate\Validation\Rules\DatabaseRule.php

/**
 * Set a "where" constraint on the query.
 *
 * @param  string|\Closure  $column
 * @param  array|string $value
 * @return $this
 */
public function where($column, $value)
{
    if (is_array($value)) {
        return $this->whereIn($column, $value);
    }

    if ($column instanceof Closure) {
        return $this->using($column);
    }

    if (!is_null($value)) {
        $this->wheres[] = compact('column', 'value');
    }

    return $this;
}

or if null add null as a value.

https://github.com/laravel/framework/blob/a784efcc17b1c683bb64b6e0916c4e2a6cea231c/src/Illuminate/Validation/Rules/DatabaseRule.php#L166

//framework\src\Illuminate\Validation\Rules\DatabaseRule.php

/**
 * Format the where clauses.
 *
 * @return string
 */
protected function formatWheres()
{
    return collect($this->wheres)->map(function ($where) {
        return $where['column'].','. ($where['value'] ?? 'null');
    })->implode(',');
}

[staudenmeir]

I don't understand your first solution. Why would you ignore a null constraint?

We could call whereNull():

public function where($column, $value)
{
    if (is_array($value)) {
        return $this->whereIn($column, $value);
    }

    if ($column instanceof Closure) {
        return $this->using($column);
    }

    if (is_null($value)) {
        return $this->whereNull($column);
    }

    return $this;
}

[set0x]

I think that is better use null (null) to ignore condition and 'null' (string) to filter by null.

This will be ignore.

$type = null;

Rule::unique('lodgings')->where('type_id', $type),

And this will be compare with null.

Rule::unique('lodgings')->whereNull('type_id'),

[driesvints]

I think @staudenmeir's suggestion is the correct solution. This probably needs to be sent to master to avoid breaking people's validation.

[driesvints]

This will be fixed in the next major release.