How to alias a table in Laravel Eloquent queries (

问题:

Lets say we are using Laravel's query builder:

$users = DB::table('really_long_table_name')
           ->select('really_long_table_name.id')
           ->get();

I'm looking for an equivalent to this SQL:

really_long_table_name AS short_name

This would be especially helpful when I have to type a lot of selects and wheres (or typically I include the alias in the column alias of the select as well, and it get's used in the result array). Without any table aliases there is a lot more typing for me and everything becomes a lot less readable. Can't find the answer in the laravel docs, any ideas?

回答1:

Laravel supports aliases on tables and columns with AS. Try

$users = DB::table('really_long_table_name AS t')
           ->select('t.id AS uid')
           ->get();

Let's see it in action with an awesome tinker tool

$ php artisan tinker
[1] > Schema::create('really_long_table_name', function($table) {$table->increments('id');});
// NULL
[2] > DB::table('really_long_table_name')->insert(['id' => null]);
// true
[3] > DB::table('really_long_table_name AS t')->select('t.id AS uid')->get();
// array(
//   0 => object(stdClass)(
//     'uid' => '1'
//   )
// )

回答2:

To use aliases on eloquent models modify your code like this:

Item
    ::from( 'items as items_alias' )
    ->join( 'attachments as att', DB::raw( 'att.item_id' ), '=', DB::raw( 'items_alias.id' ) )
    ->select( DB::raw( 'items_alias.*' ) )
    ->get();

This will automatically add table prefix to table names and returns an instance of Items model. not a bare query result. Adding DB::raw prevents laravel from adding table prefixes to aliases.

回答3:

Here is how one can do it. I will give an example with joining so that it becomes super clear to someone.

$products = DB::table('products AS pr')
        ->leftJoin('product_families AS pf', 'pf.id', '=', 'pr.product_family_id')
        ->select('pr.id as id', 'pf.name as family_name', 'pf.id as family')
        ->orderBy('pr.id', 'desc')
        ->get();

Hope this helps.

回答4:

To use in Eloquent. Add on top of your model

protected $table = 'table_name as alias'

//table_name should be exact as in your database

..then use in your query like

ModelName::query()->select(alias.id, alias.name)

回答5:

Same as AMIB answer, for soft delete error "Unknown column 'table_alias.deleted_at'", just add ->withTrashed() then handle it yourself like ->whereRaw('items_alias.deleted_at IS NULL')