this is a simplified use case, only to illustrate what I want to achieve:
Considering this query in pure SQL:
SELECT url, 1 AS active
FROM `modules`
WHERE 1
How can I add the constant active column using query builder ?
Here is my Query Builder without the extra column:
DB::table('modules')
->get(['url']);
最简单的方法是使用DB :: raw
DB::table('modules')->get(['url', DB::raw('1 as active')]);
We can add subquery or "custom column" in select with first argument of \\Illuminate\\Database\\Query\\Builder::selectSub
method as raw SQL
or Closure
, or \\Illuminate\\Database\\Query\\Builder
. Better solution is closure or Builder
. In your case it will be:
$modules = DB::table('modules')->select('url')
->selectSub(function ($query) {
$query->selectRaw('1');
}, 'active')
->get();
Tested on Laravel 5.5
. In closure $query
is a object of \\Illuminate\\Database\\Query\\Builder
for subquery. Prepared SQL will be:
select `url`, (select 1) as `active` from `modules`
Extended example... If we use App\\Module
eloquent for modules and we need get url
of modules and count
of their submodules with id > 5
, we can write next:
$modules = App\Module::select('url')
->selectSub(function ($query) {
/** @var $query \Illuminate\Database\Query\Builder */
$query->from('submodules')
->selectRaw('COUNT(*)')
->where('id', '>', 5)
->whereRaw('`modules`.`id` = `submodules`.`module_id`');
}, 'countOfSubModules')
->get();
Prepared SQL will be:
select `url`,
(select COUNT(*) from `submodules`
where `id` > ? and `modules`.`id` = `submodules`.`module_id`)
as `countOfSubModules`
from `modules`
Or you can write your example with raw sql :
$sql = 'SELECT 1';
$modules = DB::table('modules')->select('url')->selectSub($sql, 'active')->get();
Then prepared SQL will be:
select `id`, (SELECT 1) as `active` from `modules`
For get all columns necessarily to use select('*')
:
App\Module::select('*')->selectSub($sql, 'text')->get();
Not :
App\Module::selectSub($sql, 'text')->get();
Alternative solution if you are using eloquent
$people = Modules::select([
DB::raw("(SELECT 'CUSTOM_FIELD') as custom_field")
])
->get();
Laravel Eloquent has very flexible query builder.
You can specify a column to return as:
$users = DB::table('modules')->select('1 as active')->get(['url']);
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