Getting Parent name from same table - laravel

I have a table Which is as below:
quotes_glass_types
id | name | parent_id
1 | Annealed glass | Null
2 | Clear Float Glasss | 1
3 | Tinted glass | 1
4 | Toughened glass | Null
5 | Clear toughened Glass | 4
Here, name having Null parent_id are the parent.
How do i display glass name along with their parent in laravel? for example;
{
id:2,
name:Clear Float glass,
category:Annealed glass
}
what do i do after this?:
$glass=\DB::table('quotes_glass_types')->select('id','name','parent_id as category')->get();

If you want to get Name with Parent Name than you can use below query :
SELECT qgt.name,pqgt.name FROM quotes_glass_types as qgt LEFT JOIN quotes_glass_types as pqgt ON qgt.id = pqgt.parent_id
You have to use LEFT JOIN on the same table. I don't know how to write this query in Laravel but this query works in phpmyadmin.
Please check it.

You can do like this-
DB::table('quotes_glass_types')
->select('quotes_glass_types.*', 'qgt.name as parent_name')
->leftjoin('quotes_glass_types as qgt', 'qgt.id', '=', 'quotes_glass_types.parent_id')
->get();

Related

Assign id from foreign table to current table laravel

I am using laravel eloquent to get the query results. I have two tables below:
users table:
| id | department_id
| 1 | 1
| 2 | 3
| 3 | 2
department table:
| id | name
| 1 | A
| 2 | B
| 3 | C
| 4 | D
| 5 | E
How to get one unassigned ID, not existing department ID, into the users table? Example, 4 & 5 are not yet existing in users table, so how can I get 4 or 5 using an eloquent?
I am thinking of this but this is not correct.
Department::select('department.id as id')
->leftJoin('users', 'users.department_id' ,'department.id')
->pluck('id');
Does anybody know?
Try this
//here you first got all the department which is assigned to user
$assigned_dept = Users::pluck('department_id')->toArray();
$department = array_values($assigned_dept); //output:['1','3','2']
//here you can select department which is not assigned to user with limit
$user = Department::whereNotIn('id',$department)
->limit(1)->get();
hope it works for you..
You can do it like this:
Department::whereNotIn('id', User::pluck('department_id'))->get();
I believe below code will work for you :
Department::select('department.id as id')
->whereNotIn('id', User::whereNotNull('department_id')->pluck('department_id'))
->pluck('id');
From the answers others, there is a problem with the array if department_id is NULL. So, I added whereNotNull and also last() and then the problem is solved. Let me post the answer here:
Department::select('department.id as id')
->whereNotIn('id', User::whereNotNull('department_id')->pluck('department_id'))
->pluck('id')
->last(); // since I only need one row

Laravel Eloquent Model with multiple IDs

I will have a table that is full of information that involves other tables (relations). Most of the information in this table will only have the ID's of the referencing related table. If I were to use "products" as an example for this table it may look like this for some of the columns:
id | name | type_id | price_id | location_id | sale_id
----------------------------------------------------------------
1 | prod1 | 1 | 1 | 2 | 4
2 | prod2 | 2 | 1 | 1 | 1
3 | prod3 | 3 | 2 | 6 | 2
4 | prod4 | 1 | 2 | 3 | 4
I'm trying to take this "products" table and dump it out into a list. I would need to look up all of the items in these columns as I dump it out (the relation). I know how to do belongsToMany and hasMany, but I'm not sure how I can do this in one shot with an Eloquent model if I have a "products" model? Should I just make the products table just a pivot table? Can I do it with an Eloquent model or should I use query builder directly? I think if I were to use withPivot it would return the extra columns but the raw ID value from the column. I would need the value lookup from their respective table (the relation).
Tried something like this:
public function productItems(){
return $this->belongsToMany(Product::class)->withPivot(["type_id","price_id",...]);
}
As suggested by #BagusTesa, you should eager load your relations:
$products = Product::with(['type', 'price', 'location'])->get();
That will query for the related models allowing you to access them as model properties:
foreach ($products as $product){
// $product->type;
// $product->price;
// $product->location;
}

Retrieving 1 pivot row per relation based on pivot values in Laravel belongsToMany relation

Background - I'm creating a system where administrators can create arbitrary fields, which are then combined into a form. Users then complete this form, and the values input against each field are stored in a table. However, rather than overwrite the previous value, I plan on keeping each past value as individual rows in the table. I then want to be able to display the contents submitted in each form, but only the most recently submitted value.
Problem
I have a model, Service, that features a belongsToMany relationship with another model, Field. This relationship is defined as:
public function fields()
{
return $this->belongsToMany('App\Field')->withPivot('id', 'value', 'date')->withTimestamps();
}
The intermediary table has 3 values I wish to retrieve, id, value and date.
A Service may have 1 or more Fields, and for each field it may also have more than 1 pivot row. That is, a single Service/Field pairing may have multiple entries in the pivot table with different pivot values. For example:
Table field_service
id | service_id | field_id | value | created_at
------------------------------------------------------
1 | 1 | 1 | lorem | 2018-02-01
2 | 1 | 1 | ipsum | 2018-01-01
3 | 1 | 1 | dolor | 2017-12-01
4 | 1 | 2 | est | 2018-03-10
5 | 1 | 2 | sicum | 2018-03-09
6 | 1 | 2 | hoci | 2018-03-08
What I want is to get either:
A specific row from the pivot table for each Field associated with the Service, or
A specific value from the pivot table for each Field associated with the Service.
For example - in the table above, I would like the Service with ID 1 to have 2 Fields in the relationship, with each Field containing an attribute for the corresponding pivot value. The Fields attached would be specified by the corresponding pivot table entry having the most recent date. Something akin to:
$service->fields()[0]->value = "lorem"
$service->fields()[1]->value = "est"
I feel there's an obvious, 'Laravel'ly solution out there, but it eludes me...
Update
Somewhat unbelievably this is another case of me not understanding windowing functions. I asked a question 7 years ago that is basically this exactly problem, but with raw MySQL. The following raw MySQL basically gives me what I want, I just don't know how to Laravelise it:
SELECT services.name, fields.name, field_service.value, field_service.created_at, field_service.field_id
FROM field_service
INNER JOIN
(SELECT field_id, max(created_at) as ts
FROM field_service
WHERE service_id = X
GROUP BY field_id) maxt
ON (field_service.field_id = maxt.field_id and field_service.created_at = maxt.ts)
JOIN fields ON fields.id = field_service.field_id
JOIN services ON services.id = field_service.service_id
Try this:
public function fields()
{
$join = DB::table('field_service')
->select('field_id')->selectRaw('max(`created_at`) as `ts`')
->where('service_id', DB::raw($this->id))->groupBy('field_id');
$sql = '(' . $join->toSql() . ') `maxt`';
return $this->belongsToMany(Field::class)->withPivot('id', 'value', 'created_at')
->join(DB::raw($sql), function($join) {
$join->on('field_service.field_id', '=', 'maxt.field_id')
->on('field_service.created_at', '=', 'maxt.ts');
});
}
Then use it like this:
$service->fields[0]->pivot->value // "lorem"
$service->fields[1]->pivot->value // "est"

Left Outer Join via a link table, using min() to restrict join to one row

I am trying to write an Oracle SQL query to join two tables that are linked via a link table (by that I mean a table with 2 columns, each a foreign key to the primary tables). A min() function is to be used to limit the results from the left outer join to a single row.
My model consists of "parents" and "nephews". Parents can have 0 or more nephews. Parents can be enabled or disabled. Each nephew has a birthday date. The goal of my query is:
Print a single row for each enabled parent, listing that parent's oldest nephew (ie the one with the min(birthday)).
My problem is illustrated here at sqlfiddle: http://sqlfiddle.com/#!4/9a3be0d/1
I can form a query that lists all of the nephews for the enabled parents, but that is not good enough- I just want one row per parent which includes just the oldest nephew. Forming the where clause to the outer table seems to be my stumbling block.
My tables and sample data:
create table parent (parent_id number primary key, parent_name varchar2(50), enabled int);
create table nephew (nephew_id number primary key, birthday date, nephew_name varchar2(50));
create table parent_nephew_link (parent_id number not null, nephew_id number not null);
parent table:
+----+-------------+---------+
| id | parent_name | enabled |
+----+-------------+---------+
| 1 | Donald | 1 |
+----+-------------+---------+
| 2 | Minnie | 0 |
+----+-------------+---------+
| 3 | Mickey | 1 |
+----+-------------+---------+
nephew table:
+-----------+------------+-------------+
| nephew_id | birthday | nephew_name |
+-----------+------------+-------------+
| 100 | 01/01/2017 | Huey |
+-----------+------------+-------------+
| 101 | 01/01/2016 | Dewey |
+-----------+------------+-------------+
| 102 | 01/01/2015 | Louie |
+-----------+------------+-------------+
| 103 | 01/01/2014 | Morty |
+-----------+------------+-------------+
| 104 | 01/01/2013 | Ferdie |
+-----------+------------+-------------+
parent_nephew_link table:
+-----------+-----------+
| parent_id | nephew_id |
+-----------+-----------+
| 1 | 100 |
+-----------+-----------+
| 1 | 101 |
+-----------+-----------+
| 1 | 102 |
+-----------+-----------+
| 3 | 103 |
+-----------+-----------+
| 3 | 104 |
+-----------+-----------+
My (not correct) query:
-- This query is not right, it returns a row for each nephew
select parent_name, nephew_name
from parent p
left outer join parent_nephew_link pnl
on p.parent_id = pnl.parent_id
left outer join nephew n
on n.nephew_id = pnl.nephew_id
where enabled = 1
-- I wish I could add this clause to restrict the result to the oldest
-- nephew but p.parent_id is not available in sub-selects.
-- You get an ORA-00904 error if you try this:
-- and n.birthday = (select min(birthday) from nephew nested where nested.parent_id = p.parent_id)
My desired output would be:
+-------------+-------------+
| parent_name | nephew_name |
+-------------+-------------+
| Donald | Louie |
+-------------+-------------+
| Mickey | Ferdie |
+-------------+-------------+
Thanks for any advice!
John
markaaronky's suggestion
I tried using markaaronky's suggestion but this sql is also flawed.
-- This query is not right either, it returns the correct data but only for one parent
select * from (
select parent_name, n.nephew_name, n.birthday
from parent p
left outer join parent_nephew_link pnl
on p.parent_id = pnl.parent_id
left outer join nephew n
on n.nephew_id = pnl.nephew_id
where enabled = 1
order by parent_name, n.birthday asc
) where rownum <= 1
Why not:
(1) include the n.birthday from the nephews table in your SELECT statement
(2) add an ORDER BY n.birthday ASC to your query
(3) also modify your select so that it only takes the top row?
I tried to write this out in sqlfiddle for you but it doesn't seem to like table aliases (e.g. it throws an error when I write n.birthday), but I'm sure that's legal in Oracle, even though I'm a SQL Server guy.
Also, if I recall correctly, Oracle doesn't have a SELECT TOP like SQL Server does... you have to do something like "WHERE ROWNUM = 1" instead? Same concept... you're just ordering your results so the oldest nephew is the first row, and you're only taking the first row.
Perhaps an undesired side effect is you WOULD get the birthday along with the names in your results. If that's unacceptable, my apologies. It looked like your question has been sitting unanswered for a while and this solution should at least give you a start.
Lastly, since you don't have a NOT NULL constraint on your birthday column and are doing left outer joins, you might make the query safer by adding AND n.birthday IS NOT NULL
Use:
select parent_name, nephew_name
from parent p
left outer join
(
SELECT pnl.parent_id, n.nephew_name
FROM parent_nephew_link pnl
join nephew n
on n.nephew_id = pnl.nephew_id
AND n.BIRTHDAY = (
SELECT min( BIRTHDAY )
FROM nephew n1
JOIN parent_nephew_link pnl1
ON pnl1.NEPHEW_ID = n1.NEPHEW_ID
WHERE pnl1.PARENT_ID = pnl.PARENT_ID
)
) ppp
on p.parent_id = ppp.parent_id
where p.enabled = 1
Demo: http://sqlfiddle.com/#!4/98758/23
| PARENT_NAME | NEPHEW_NAME |
|-------------|-------------|
| Mickey | Louie |
| Donald | Ferdie |

how to group by desc order in hql

I have the following table called questions in HQL Hibernate:
ID | Name
1 | Bread
2 | Bread
3 | Rise
4 | Rise
I want to select each PRODUT only once and if there are multiple PRODUCT with the same name, select the one of the highest id. So, the expected results:
ID | NAME
3 | Bread
4 | Rise
I use the following query:
from Product AS E group by E.producto
So it selects the first 'Product' it encounters instead of the last one.
Thanks
The syntax is almost identical to SQL:
select max(p.id), p.name from Product p group by p.name
Relevant documentation:
http://docs.jboss.org/hibernate/core/4.3/manual/en-US/html/ch16.html#queryhql-aggregation
http://docs.jboss.org/hibernate/core/4.3/manual/en-US/html/ch16.html#queryhql-grouping

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