Laravel MySQL，其中封包无法按预期工作

Question

Can anyone help to explain why one of the following Laravel queries works and the other doesn't?

The first that works:

$array = ( 1, 2, 3 ,4 );
$query->whereIn( 'status_id', $array );

This works as expected. However, when I try and pass a function to build my array:

$query->whereIn( 'status_id', function() use ( $statuses ){
    $status_array = array();
    foreach( $statuses as $status ){
         $status_array[] = $status->status_id;
    }

    return $status_array;
});

I get the following error:

General error: 1096 No tables used (SQL: select * from jobs where status_id in (select *))

I have checked to see that the array I am building in the closure is the same as the array that works, and it is. Am I missing something fundamental regarding whereIn() and it's closure functions? Can I even pass a closure to whereIn()?

Answer 1

As a related answer, instead of running a loop to generate your list - just have Laravel do it for you

 $status_array= DB::table('status')->lists('status_id');

then use it

 $query->whereIn( 'status_id', $status_array );

Answer 2

When you use a closure in whereIn() , Laravel will think that you will be doing a sub query. Hence you see another select inside your in in your error message.

You'll need to parse your array of values before passing to the whereIn()

foreach ($statuses as $status) {
     $status_array[] = $status->status_id;
}

$query->whereIn('status_id', $status_array);

---

Extra: See reference to Laravel source.

Illuminate\\Database\\Query\\Builder :

public function whereIn($column, $values, $boolean = 'and', $not = false)
{
    ...

    if ($values instanceof Closure)
    {
        return $this->whereInSub($column, $values, $boolean, $not);
    }
}

which calls whereInSub() :

protected function whereInSub($column, Closure $callback, $boolean, $not)
{
    $type = $not ? 'NotInSub' : 'InSub';

    // To create the exists sub-select, we will actually create a query and call the
    // provided callback with the query so the developer may set any of the query
    // conditions they want for the in clause, then we'll put it in this array.
    call_user_func($callback, $query = $this->newQuery());

    $this->wheres[] = compact('type', 'column', 'query', 'boolean');

    $this->mergeBindings($query);

    return $this;
}

Answer 3

I think your function returns an array like this one:

[ 0 => status_id_value_0,
  1 => status_id_value_1, 
  ...
] 

Try to return an array_values($status_array) to check it.

Anyway, try this one too:

$query->whereIn( 'status_id', 
                 array_values(
                     array_map(
                         function($pos){return $pos->status_id;},
                         $statuses
                     )
                 )
               ); 

I hope it works fine for you.

Answer 4

You need to convert comma separated value to array before passing to whereIN.

and this is also good for any dynamic content

    foreach ($statuses as $status) {
         $status_array[] = $status->status_id;
    }
    $query->whereIn('status_id', $status_array);