Don't add BelongsToMany relation column to select

[affaron]

It seems like a part of "duplicate column" problems with sorting/filtering by BelongsToMany relation column are coming from this.

When you have same column names in your main and relation tables adding a ->select() is not helping because the relation column is still added in joinEagerLoadedColumn(). And depending on the situation either your main model column will be populated with same name relation column or you're getting an error in your aggregate queries. Example:

Exception Message:

SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'name' (SQL: select count(*) as aggregate from (select `crm_companies`.`id`, `crm_companies`.`name`, `dic_company_types`.`name` from `crm_companies` left join `crm_company_types` on `crm_company_types`.`company_id` = `crm_companies`.`id` left join `dic_company_types` on `crm_company_types`.`type_id` = `dic_company_types`.`id` where LOWER(`dic_company_types`.`name`) LIKE %clearing agent% group by `crm_companies`.`name`) count_row_table)

(crm_companies.name is the main model column, dic_company_types.name - automatically added relation column and hence the conflict)

So I look into the code and found this place. $this->performJoin($table, $foreign, $other); looks unnecessary since it's performed anyway after the switch block and addSelect is adding a relation column that doesn't seem to be required and causes duplicates. Please correct me if I'm wrong.

Thanks

[yajra]

Per @dragonfly4 feedback, PR doesn't fixed the issue.

I tested that but it's not fixing the issue above. Same error.

[affaron]

Hey, sorry, didn't have time to get back to this. I reverted those changes from a merge I did into this branch back then. Didn't realise that it'd affect this request.

Anyway, it still seems that adding that addSelect (even the recent one in HasOneThrough case) causes some column names duplicating when you sort/search (if you already have select attached before). Maybe it's best to remove them and suggest users to use selects (it was already suggested as I recall).

I'll try to look into this issue again later.

[turdakhov]

I have duplicates without using select.
I solved it this way:
return $this->belongsToMany(Characteristic::class)->distinct()->with('values');