仅从联接表中获取选定的列

Question

I have this reference code below, first the line 1 will get

$aa = users_details::select(array('id', 'user_id'))->where('id', '=', $request->id)->first(); //first line
$bb = User::select(array('user_id'))->where('user_id', '=', $aa->id)->with('user_details')->first(); //second line

the first line returns 13 which is correct while the second line returns 'null' which it should not because there's actually a record that has a user_id of '13'. Any ideas, help please?

and also is there a way I could select only selected columns in this join table (Eloquent relationship hasOne)

$bb = User::select(array('user_id'))->where('user_id', '=', $aa->id)->with('user_details')->first();

I dont know if

select(array('user_id'))

is the right one to select only selected columns from the join table. Any ideas, help, please?

Answer 1

First Question:

$bb = User::select(array('user_id'))->where('user_id', '=', $aa->id)->with('user_details')->first();

Do you have user_id column in users (or anywhere User Model refers to) table? Do you have user_details method in User model?

Second Question:

You can select as

User::select('user_id', 'username', 'sex')

If you have same column name in the joined table, then you can select as

User::select('users.user_id as a', 'users.username', 'users.sex', 'user_details.user_id as b')

UPDATE:

How can I select only selected column from the 'user_details' when both is joining togehter?

User::select('users.user_id as user_id', 'users.username', 'users.sex', 'user_details.user_id as user_details_id')->join('user_details','user_details.user_id','=', 'users.id' )->where('users.id', '=', $aa->id)->first();

To select the columns from the joined table, just prefix the column name with table name such as user_details.user_id .