How to query field created by addSelect in Laravel? - php

Question

I have the following query where I am adding three new columns by using the addSelect function
DB::connection('mysql_slave')
->table('applications')
->whereNull('applications.deleted_at')
->when($column != 'contract_return_date' && $column != 'contract_delivery_date',function ($query) use ($column,$date_from,$date_to){
return $query->whereBetween('applications.'.$column, [$date_from, $date_to]);
})
->join('customers','applications.customer_id','=','customers.id')
->join('departments','applications.department_id','=','departments.id')
->select([
'applications.id',
'applications.customer_id',
DB::raw('CONCAT(IFNULL(customers.last_name,"")," ",customers.first_name ) as customers_name'),
DB::raw('CONCAT(IFNULL(applications.last_name,"")," ",applications.first_name ) as contract_name'),
'applications.offer_type as offer_type',
'applications.status_id',
'applications.contract_no',
'applications.current_provider',
'applications.extra_offer',
'applications.offer_warranty',
'applications.department_id',
'customers.mobile_phone as customer_mobile',
'applications.program as program',
'applications.saled_by_text as saler',
'departments.name as department',
'applications.created_at as created_at',
'applications.created_at as saled_at',
DB::raw('IF(applications.sale=1,"NAI","OXI") as sale'),
])
->addSelect(['submission_date'=> StatusLog::select('created_at')
->whereColumn('application_id','applications.id')
->where('status','=',1)
->latest()
->take(1)
])
->addSelect(['resubmission_date'=> StatusLog::select('created_at')
->whereColumn('application_id','applications.id')
->where('status','=',2)
->latest()
->take(1)
])
->addSelect(['error_date' => StatusLog::select('created_at')
->whereColumn('application_id','applications.id')
->whereIn('status', [5, 6])
->latest()
->take(1)
]) ->when($column == 'contract_delivery_date',function ($query) use ($date_from,$date_to){
return $query->whereBetween('submission_date', [$date_from, $date_to]);
});
The above query is used to print data on a datatable.
The query includes columns that were added using the addSelect function, and these columns are being displayed correctly on the table.
However, when I try to query the submission_date field, I am encountering an error:
1054 Unknown Column submission_date.
Is there a way to query columns that were created using the addSelect function in Laravel?
Thank you for your help and I apologize for any errors in my English.

Answer 1

I think you cant do this. The custom select field (submission_date) is computed after the main query results. This is a limitation of the Database.
But you can use the HAVING operator instead.
https://stackoverflow.com/a/67580272/6901915

Answer 2

You do not create a field using addSelect. You only add a field to your query, so you cannot query it. Let's consider an example:
create table abc(id int primary key);
is a table I created as a proof-of-concept. Now, let's fill in some data:
insert into abc(id)
values(1),(2);
Now, let's query it, adding a field to it, called foo:
select id, 2 * id as foo
from abc;
And, now let's filter by foo:
select id, 2 * id as foo
from abc
where foo = 2;
We get an error, see below:
So, if you want to add a field and query by it, then you will need to either hardcode the field's equivalent into your conditional OR create a view of the table where the field exists OR add the field to the table.