Eloquent query alternative - laravel

How can I write the following in Laravel's Eloquent?
SELECT *
FROM
( SELECT real_estate.property_id,
real_estate.amount_offered,
payee.summa
FROM real_estate
LEFT JOIN
(SELECT property_id,
SUM(amount) AS summa
FROM payments
GROUP BY property_id) payee ON payee.property_id = real_estate.property_id ) yoot
WHERE summa = 0.05 * amount_offered
Been on this for a while now and really can't get around it. Lemme explain the whole cause for the panic.
I have two tables, one for property and another for payments made on those properties. Now at any given time I will like to query for what properties have been paid for to a certain percentage hence the 0.05 which reps 5%. As it is the query works but I need an Eloquent alternative for it. Thanks

Anywhere you have subqueries in your SQL you'll need to use DB::raw with Eloquent. In this case you have a big subquery for the FROM statement, so the easiest way would be to do this:
DB::table(
DB::raw('SELECT real_estate.property_id, real_estate.amount_offered, payee.summa FROM real_estate LEFT JOIN (SELECT property_id, SUM(amount) AS summa FROM payments GROUP BY property_id) payee ON payee.property_id = real_estate.property_id)')
)
->where('summa', DB::raw('0.05 * amount_offered'))->get();
Notice I used DB::raw for the WHERE statment value as well. That's because you are doing a multiplication using a column name, and the value would otherwise be quoted as a string.
If you want to go a step further and build each subquery using Eloquent, then convert it to an SQL string and injecting it using DB::raw, you can do this:
$joinQuery = DB::table('payments')
->select('property_id', 'SUM(amount) AS summa')
->groupBy('property_id')
->toSql();
$tableQuery = DB::table('real_estate')
->select('real_estate.property_id', 'real_estate.amount_offered', 'payee.summa')
->leftJoin(DB::raw('(' . $joinQuery . ')'), function ($join)
{
$join->on('payee.property_id', '=', 'real_estate.property_id');
})
->toSql();
DB::table(DB::raw('(' . $tableQuery . ')'))->where('summa', DB::raw('0.05 * amount_offered'))->get();
In this case, the second approach doesn't have any benefits over the first, except perhaps that it's more readable. However, building subqueries using Eloquent, does have it's benefitfs when you'd need to bind any variable values to the query (such as conditions), because the query will be correctly built and escaped by Eloquent and you would not be prone to SQL injection.

Related

How can I write the below pure SQL statement in laravel without using DB:raw

I'm trying to show the total price according to month. I know how to retrieve the data with pure SQL statements but I don't know a way to apply it inside Laravel. And also I don't want to use DB::raw(). I need help!! Below is the pure SQL statement.
SELECT month(dt.created_at) as Month,SUM(dp.price) as Total_Price
FROM datapack_transactions dt
INNER JOIN datapack_packages dp ON dt.package_id=dp.id
GROUP BY month(dt.created_at);
Below is the result of the above pure SQL statement.
I want to use the Laravel Eloquent instead of using DB::raw().
Try this query:
$orders = datapack_transactions::select(
DB::raw('month(datapack_transactions.created_at) as Month'),
DB::raw("SUM(datapack_packages.price) as Total_Price")
)
->join('datapack_packages','datapack_packages.id','=','datapack_transactions.package_id')
->groupBy('datapack_transactions.created_at')
->get();
//Change model and columns as per yours

Need guidance on how to build a Laravel database query

In Laravel 6.18 I'm trying to figure out how to recreate the following Postgres query.
with data as (
select date_trunc('month', purchase_date) as x_month, date_trunc('year', purchase_date) AS x_year,
sum (retail_value) AS "retail_value_sum"
from coins
where user_email = 'user#email.com' and sold = 0
group by x_month, x_year
order by x_month asc, x_year asc
)
select x_month, x_year, sum (retail_value_sum) over (order by x_month asc, x_year asc rows between unbounded preceding and current row)
from data
I know how to build the main part of the query
$value_of_all_purchases_not_sold = DB::table('coins')
->select(DB::raw('date_trunc(\'month\', purchase_date) AS x_month, date_trunc(\'year\', purchase_date) AS x_year, sum(retail_value) as purchase_price_sum'))
->where('user_email', '=', auth()->user()->email)
->where('sold', '=', 0)
->groupBy('x_month', 'x_year')
->orderBy('x_month', 'asc')
->orderBy('x_year', 'asc')
->get();
but how do you build out the with data as ( and the second select?
I need the data to be cumulative and I'd rather do the calculation in the DB than in PHP.
Laravel doesn't have built-in method(s) for common table expression. You may use a third party package such as this - it has a very good documentation. If you don't want to use an external library, then you need use query builder's select method with bindings such as
$results = DB::select('your-query', ['your', 'bindings']);
return Coin::hydrate($results); // if you want them as collection of Coin instance.

In Laravel Eloquent, how do I reference primary query in subquery

I have a model User that has many Orders. Orders have many products, with the pivot table order-product. I don't want to preload and iterate through the orders if at all possible.
I need to return users where
signed_date === true on User
order_date on Order is after signed_date on User
order-product shows product hasn't been paid
I am failing on number 2.
In the following code, the first query within whereHas is wrong. I don't know how to reference the signed date of the user from within the where has. If I was iterating through users in a collection I could do something like ($query) use $user, but how do I do this without preloading all the users?
return User::whereNotNull('signed_date')
->whereHas('orders', function ($query) {
$query->where('order_date', '<=', 'user.signed_date');
$query->whereHas('products', function ($q) {
$q->where('paid', false);
});
})
->get(['id','fname','lname', 'title', 'signed_date']);
I would like to use eloquent if possible. If that is not possible, I would be happy for tips in solving this problem using the query builder/sql.
The Eloquent query builder has a special function called whereColumn('a', '<=', 'b') to compare columns instead of a column against a value. Using this function instead of a normal where() is necessary because of the way the query builder builds the actual query. You need to let the query builder know that you are going to pass a column name instead of a value for proper escaping and formatting of the query string.
Anyway, it seems you can also pass column names prefixed with a table name to the function, allowing you to compare columns across tables:
$query->whereColumn('orders.order_date', '<=', 'users.signed_date')
This works because you are using whereHas() in your query. Your query basically gets translated to:
SELECT id, fname, lname, title, signed_date
FROM users
WHERE signed_date NOT NULL
AND EXISTS (
SELECT 1
FROM orders
WHERE orders.order_date <= users.signed_date
AND EXISTS (
SELECT 1
FROM products
WHERE paid = 0
)
)
It might actually be not necessary at all to use the table name together with the column name in whereColumn(). But in case you'll ever add a column named the same on another table, the query might break - so IMHO it is good practice to use the table name in custom queries.
By the way, the reason this will not work together with with('relationship') is that this function results in an additional query and you obviously cannot compare columns across queries. Imagine the following:
Order::with('user')->take(5)->get();
It will be translated into the following:
SELECT *
FROM orders
LIMIT 5
SELECT *
FROM users
WHERE id IN (?, ?, ?, ?, ?)
where the five ? will be the user_ids of the orders. If the first query returns multiple rows with the same user_id, the amount of rows fetched from the users table gets reduced of course.
Note: All the queries are only examples. Might be that the query builder builds different queries based on the database type and/or escapes them differently (i.e. column names in backticks).

Converting a raw query to Laravel query builder

I have the following MySQL query which fetches a list of the last 9 authors to write a post and lists them in order of the date of the last post they wrote.
It's working properly but I'd like to re-write it using the Laravel Query Builder. Here is the query at the moment:
$authors = DB::select("
SELECT
`a`.`id`,
`a`.`name`,
`a`.`avatar`,
`a`.`slug` AS `author_slug`,
`p`.`subheading`,
`p`.`title`,
`p`.`slug` AS `post_slug`,
`p`.`summary`,
`p`.`published_at`
FROM
`authors` AS `a`
JOIN
`posts` AS `p`
ON `p`.`id` =
(
SELECT `p2`.`id`
FROM `posts` AS `p2`
WHERE `p2`.`author_id` = `a`.`id`
ORDER BY `p2`.`published_at` DESC
LIMIT 1
)
WHERE
`a`.`online` = 1
ORDER BY
`published_at` DESC
LIMIT 9
");
I understand the basics of using the query builder, but there doesn't appear to be anything in the Laravel docs that allows for me to JOIN a table ON a SELECT.
Can anyone suggest a way that I can write this query using the Laravel Query builder, or perhaps suggest a way that I can rewrite this query to make it easier to structure with the query builder?
Try to do like this
$data = DB::table('authors')
->select(
'a.id',
'a.name',
'a.avatar',
'a.slug AS author_slug',
'p.subheading',
'p.title',
'p.slug AS post_slug',
'p.summary',
p.published_at')
->from('authors AS a')
->join('posts AS p', 'p.id', '=', DB::raw("
(
SELECT p2.id FROM posts AS p2
WHERE p2.author_id = b.id
ORDER BY p2.published_at
DESC LIMIT 1
)"))
->where('a.online', 1)
->limit(9)
->orderBy('p.published_at', 'desc')
->get();

Select rows having 2 columns equal value in laravel Query builder

I want to write a query which selects rows where 2 attributes from 1 entity have equal value.
This would be an example of doing this in raw SQL:
Select * from users u where u.username = u.lastname
Does laravel have any methods that take 2 column names as parameters and return the matching results?
What you need is a DB::raw expression:
DB::table('users')
->where('username', '=', DB::raw('lastname'))
->get();
The only thing DB::raw actually does is to tell the query interpreter not to treat 'lastname' like any other string value but just interpolate it in the SQL as it is.
http://laravel.com/docs/queries#raw-expressions
In Laravel 5, there's now whereColumn for this, for cleaner code:
Users::whereColumn('username', 'lastname')->get();

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