laravel simple query builder (join & where case) - sql

Question

i have 2 table (product & type)
produk table
-id
-kode_produk
-nama_produk
-id_jenis_produk
and
jenis table
- id
- jenis_item
i wanna access database jenis_item from jenis tablewith query builder
so far i already try
$selectProduk = DB::table('produk')->where('id', $id)->join('jenis', 'produk.id_jenis_produk', '=', 'jenis.id')->first();
and something like this
$selectProduk = DB::table('produk')
->join('jenis', function($join) {
$join->on('produk.id_jenis_item', '=', 'jenis.id')
->where('produk.id', $id); // line 86 (error)
})->first();
but still failed with message error from laravel logs
exception 'ErrorException' with message 'Undefined variable: id' in C:\xampp\htdocs\itklan\app\controllers\ProdukController.php:86
where i'm missing?
#Thomas Kim
i get another error
exception 'ErrorException' with message 'Missing argument 3 for Illuminate\Database\Query\JoinClause::where(), called in C:\xampp\htdocs\itklan\app\controllers\ProdukController.php on line 86 and defined' in C:\xampp\htdocs\itklan\vendor\laravel\framework\src\Illuminate\Database\Query\JoinClause.php:87
line 87 :
$selectProduk = DB::table('produk')
->join('jenis', function($join) use($id) {
$join->on('produk.id_jenis_item', '=', 'jenis.id')
->where('produk.id', $id);
})->first(); //line 87

Answer 1

This is how PHP closures work. In order to use $id, the closure must inherit the variable from the parent scope by using the use keyword. For example:
$selectProduk = DB::table('produk')
->join('jenis', function($join) use($id) { // Check this line
$join->on('produk.id_jenis_item', '=', 'jenis.id')
->where('produk.id', '=', $id);
})->first();
Closures may also inherit variables from the parent scope. Any such variables must be passed to the use language construct.
Source: http://php.net/manual/en/functions.anonymous.php
Edit:
Also, looks like with Laravel's JoinClause, you need to be specific about your operators. Normally, you can do this:
->where('produk.id', $id);
And Laravel adds an equal operator for you. However, for join clauses, this will not work. You need to specify the operator.
->where('produk.id', '=', $id);