Laravel using UNION in query builder - php

I have an SQL query that works fine and I'm trying to convert into fluent::
SELECT DISTINCT tags.tag
FROM tags, items
WHERE tags.taggable_type = 'Item'
AND items.item_list_id = '1'
UNION
SELECT DISTINCT tags.tag
FROM tags, itemlists
WHERE tags.taggable_type = 'ItemList'
AND itemlists.id = '1'
This is what I have so far in fluent, it all seems right as far as I can tell from the docs and the individual queries both work on their own, it's just when I UNION them it throws an error:
$itemTags = Tag::join('items', 'items.id', '=', 'tags.taggable_id')
->select('tags.tag')
->distinct()
->where('tags.taggable_type', '=', 'Item')
->where('items.item_list_id', '=', $itemList->id);
$itemListTags = Tag::join('itemlists', 'itemlists.id', '=', 'tags.taggable_id')
->select('tags.tag')
->distinct()
->where('tags.taggable_type', '=', 'ItemList')
->where('itemlists.id', '=', $itemList->id);
// the var_dump below shows the expected results for the individual queries
// var_dump($itemTags->lists('tag'), $itemListTags->lists('tag')); exit;
return $itemTags
->union($itemListTags)
->get();
I get the following error when I run it (I've also swapped from Ardent back to Eloquent on the model in case that made a difference - it doesn't):
Argument 1 passed to Illuminate\Database\Query\Builder::mergeBindings() must be an instance of Illuminate\Database\Query\Builder, instance of LaravelBook\Ardent\Builder given, called in path/to/root\vendor\laravel\framework\src\Illuminate\Database\Query\Builder.php on line 898 and defined

Looks like your models are using Ardent, not Eloquent:
...instance of LaravelBook\Ardent\Builder given, ...
And probably this might be a problem on Ardent, not Laravel.
Open an issue here: https://github.com/laravelbook/ardent.
EDIT:
Try to change use QueryBuilder instead of Eloquent:
Use this for QueryBuilder:
DB::table('tags')->
Instead of the Eloquent way:
Tag::

I know you mentioned wanting to use the query builder, but for complex queries that the builder might throw fits on, you can directly access the PDO object:
$pdo = DB::connection()->getPdo();

Related

Need help for my sql query to make use of AS operator [duplicate]

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 gets 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?
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'
// )
// )
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.
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 product_family_name', 'pf.id as product_family_id')
->orderBy('pr.id', 'desc')
->get();
Hope this helps.
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)
You can use less code, writing this:
$users = DB::table('really_long_table_name')
->get(array('really_long_table_name.field_very_long_name as short_name'));
And of course if you want to select more fields, just write a "," and add more:
$users = DB::table('really_long_table_name')
->get(array('really_long_table_name.field_very_long_name as short_name', 'really_long_table_name.another_field as other', 'and_another'));
This is very practical when you use a joins complex query
I have tried all these options and none works for me. Then I had found something in the Laravel documentation that really works.
You could try this:
DB::table('table_one as t1')
->select(
't1.field_id as id','t2.field_on_t2 as field'
)->join('table_two as t2', function ($join) {
$join->on('t1.field_id ', '=', 't2.field_id');
})->get()
Also note that you can pass an alias as the second parameter of the table method when using the DB facade:
$users = DB::table('really_long_table_name', 'short_name')
->select('short_name.id')
->get();
Not sure if this feature came with a specific version of Laravel or if it has always been baked in.
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')
In the latest version of Laravel 9, you can use alias name for column as:
$events = Booking::whereBetween('sessionDateTime', [$today, $nextMonth])->get(['bookings.sessionDateTime as start']); // start is an alias here

Eloquent queries work separately but not together in a subquery

I'm trying to fetch some data with a subquery using Eloquent but dding returns nothing. Separately, this
$discountArticles = $discountTableItemIdIn
->where('recipient_type', '=', 'article')
->toArray();
or this
$discountArticles = $discountTableItemIdIn
->where('recipient_id', '=', $articleId)
->toArray();
work fine.
However when I try something like this, it fails (or rather, returns nothing):
$discountArticles = $discountTableItemIdIn->where(function ($subQuery) {
$subQuery
->where('recipient_type', '=', 'article')
->where('recipient_id', '=', $articleId);
})->toArray();
I know I can do separate queries on the same collection and do an array_merge but I'd like to get this way working instead. Not sure what's happening.
So $discountTableItemIdIn is a collection of the entire table? That means you're gonna need a different function, as the ->where() logic on a collection is different from how it functions on a builder (eloquent) instance.
Try using filter():
$discountArticles = $discountTableItemIdIn->filter(function ($item) use($articleId) {
return $item->recipient_type == "article" && $item->recipient_id == $articleId;
})->toArray();
What this will do is filter your $discountTableItemIdIn collection for records that have a type of article and a recipient_id of whatever $articleId contains, return a new collection and convert that to an array.
Just a note, this is quite inefficient; you should try to avoid loading the whole table into a collection and just query the table directly using the subquery logic in your question.

Assign a query to variable to then perform two separate queries?

Is it possible to start an eloquent query, assign it to a variable then continue using the variable for two separate queries without them conflicting with one another. A simple example:
$students = $this->student
// more query stuff
->where('is_active', 1);
$bachelorStudents = $students
->where('course_id', 3)
->get();
$masterStudents = $students
->where('course_id', 4)
->get();
or would I need to do:
$bachelorStudents = $this->student
->where('course_id', 3)
->get();
$masterStudents = $this->student
->where('course_id', 4)
->get();
I always thought I could do the former, but some of my results appear to show I can't but I am open to believe that if you can do it then perhaps I'm doing something wrong.
When you're calling
$students = $this->student->where('is_active', 1);
you're creating a query builder object. Calling where*() on this object updates the object by adding given criteria. Therefore it's not possible to achieve what you want in your first code snippet, because when you call
$masterStudents = $students
->where('course_id', 4)
->get();
the query builder already contains where('course_id', 3) constraint added when you bachelorStudents.
Once you do that:
$students = $this->student->where('is_active', 1);
$stundents will contain a query builder with your where clause
If you do:
$bachelorStudents = $students->where('course_id', 3)->get();
You'll add another where clasuse to the $students builder, and this should work as you expect
But, when you do:
$masterStudents = $students->where('course_id', 4)->get();
You are adding another where clasuse to the same $students builder, thus resulting the query builder to be something like this:
$students->where('is_active', 1)
->where('course_id', 3)
->where('course_id', 4)
->get();
That probably isn't what you expect, because you have 2 where clauses with different course_id values
Think of $student as an object you modify everytime you add a clause, so you can use it for progressive query building, but remember that once you've added a clause to the query builder, the object is modified and the clause will be keept in the builder, so when you re-use the builder it will contain all the clasuses you previously added
Also, Rembember that when you need to apply some pre-defined filters to your query, in Laravel you should use query scopes
While everyone is explaining query builder and how it works, here's your answer.
1) Start off your query builder
$studentsQuery = $this->student
//Start a new query builder (optional)
->newQuery()
->where('is_active', 1);
2) Clone the initial query builder to our separate queries
$bachelorStudentsQuery = clone $studentsQuery;
$masterStudentsQuery = clone $studentsQuery;
3) Assign your where conditions and get the results
$bachelorStudentsResult = $bachelorStudentsQuery->where('course_id', 3)
->get();
$masterStudentsResult = $masterStudentsQuery->where('course_id',4)
->get();
Your use case is too simple for cloning.
It might help you DRY your code when lots of method chaining has been performed, especially when applying filters to queries.

Different values when use DB::raw() in second param on where()

I have next query in Laravel Eloquent:
$buildings = Building::select('buildings.*')->join(
DB::raw('('.
(
IngameBuilding::select('buildings.building_id', 'buildings.level')
->join('buildings', 'buildings.id', '=', 'ingame_buildings.building_id')
->toSql()
).
') as `added_buildings`'), 'added_buildings.building_id', '=', 'buildings.building_id')
->where('buildings.level', '>', 'added_buildings.level')
->get();
This query returns all allowed rows from base, but one row more. When I added DB::raw() in where() return values is valid.
Good-working code:
$buildings = Building::select('buildings.*')->join(
DB::raw('('.
(
IngameBuilding::select('buildings.building_id', 'buildings.level')
->join('buildings', 'buildings.id', '=', 'ingame_buildings.building_id')
->toSql()
).
') as `added_buildings`'), 'added_buildings.building_id', '=', 'buildings.building_id')
->where('buildings.level', '>', DB::raw('`added_buildings`.`level`'))
->get();
Why first code workig, hmm.. Wrong?
I'm not a big fan of Laravel at all.
I've got only small experience with this framework but i'm almost sure that where function accepts only a 'constant' values to be checked against.
If you'll get an output of this query using toSQL method on the query object you will see that eloquent will convert it as something like:
(...) where buildings.level > 'added_buildings.level'
so the condition checks if the buildings.level (whatever the type is)
is greater than the given string and not the column value.
Using the DB::raw you're getting the proper sql as the eloquent won't parse/convert it.
You would need to use whereRaw method I suppose.
http://laravel.com/docs/4.2/queries#introduction

How to alias a table in Laravel Eloquent queries (or using Query Builder)?

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 gets 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?
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'
// )
// )
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.
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 product_family_name', 'pf.id as product_family_id')
->orderBy('pr.id', 'desc')
->get();
Hope this helps.
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)
You can use less code, writing this:
$users = DB::table('really_long_table_name')
->get(array('really_long_table_name.field_very_long_name as short_name'));
And of course if you want to select more fields, just write a "," and add more:
$users = DB::table('really_long_table_name')
->get(array('really_long_table_name.field_very_long_name as short_name', 'really_long_table_name.another_field as other', 'and_another'));
This is very practical when you use a joins complex query
I have tried all these options and none works for me. Then I had found something in the Laravel documentation that really works.
You could try this:
DB::table('table_one as t1')
->select(
't1.field_id as id','t2.field_on_t2 as field'
)->join('table_two as t2', function ($join) {
$join->on('t1.field_id ', '=', 't2.field_id');
})->get()
Also note that you can pass an alias as the second parameter of the table method when using the DB facade:
$users = DB::table('really_long_table_name', 'short_name')
->select('short_name.id')
->get();
Not sure if this feature came with a specific version of Laravel or if it has always been baked in.
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')
In the latest version of Laravel 9, you can use alias name for column as:
$events = Booking::whereBetween('sessionDateTime', [$today, $nextMonth])->get(['bookings.sessionDateTime as start']); // start is an alias here

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