Converting SQL Queries to Laravel Query Builder
In this tutorial, we will cover how to convert a given SQL query into an equivalent Laravel query using the query builder. We’ll explore different approaches and techniques for achieving this conversion.
Understanding the Problem Statement
The provided SQL query is:
SELECT
c.*
FROM
merchantlink m,
company c,
merchantlinkrelation mlr
WHERE
(m.initiator_user_id = c.owner_user_id AND
m.responder_user_id = 86 AND
mlr.ptype='dealer')
OR
(m.initiator_user_id = 86 AND
m.responder_user_id = c.owner_user_id AND
mlr.ptype = 'dealer')
OR
(m.initiator_user_id = c.owner_user_id AND
c.owner_user_id=86 AND
mlr.ptype='dealer')
GROUP BY
c.id;
This query involves three tables (merchantlink, company, and merchantlinkrelation) with various conditions to filter the results.
Introduction to Laravel’s Query Builder
Laravel provides a powerful query builder that allows you to construct queries in a more readable and maintainable way. The query builder is built on top of the database abstraction layer (DBAB) and provides an object-oriented interface for constructing queries.
To use the query builder, we need to create an instance of DB using Laravel’s container system. Here’s how it’s done:
use Illuminate\Support\Facades\DB;
// Create a new DB instance
$db = DB::connection('default');
// Now you can use the $db object to construct queries
Converting SQL Queries to Laravel Query Builder
Now that we have an understanding of the query builder, let’s dive into converting our SQL query.
Method 1: Using join() and whereRaw()
One way to convert the SQL query is by using the join() method and whereRaw() for more complex conditions. Here’s how it can be done:
// Create a new DB instance
$db = DB::connection('default');
// Construct the query using join() and whereRaw()
$twowaycompany = $db->table('company')
->join('merchantlink', 'merchantlink.responder_user_id', '=', 'company.owner_user_id')
->join('merchantlinkrelation', 'merchantlinkrelation.merchantlink_id', '=', 'merchantlink.id')
->whereRaw("(m.initiator_user_id = c.owner_user_id AND m.responder_user_id = 86 AND mlr.ptype = 'dealer')")
->orWhereRaw("(m.initiator_user_id = 86 AND m.responder_user_id = c.owner_user_id AND mlr.ptype = 'dealer')")
->orWhereRaw("(m.initiator_user_id = c.owner_user_id AND c.owner_user_id = 86 AND mlr.ptype = 'dealer')")
->groupBy('c.id')
->pluck('name')
->toArray();
Method 2: Using join() and where() with multiple conditions
Another way to convert the SQL query is by using the join() method and where() for more complex conditions. Here’s how it can be done:
// Create a new DB instance
$db = DB::connection('default');
// Construct the query using join() and where()
$twowaycompany = $db->table('company')
->join('merchantlink', 'merchantlink.initiator_user_id', '=', 'company.owner_user_id')
->join('merchantlinkrelation', 'merchantlinkrelation.merchantlink_id', '=', 'merchantlink.id')
->where(function ($query) {
$query->where('m.responder_user_id', '=', 86)
->orWhere('c.owner_user_id', '=', 86);
})
->whereRaw("mlr.ptype = 'dealer'")
->groupBy('c.id')
->pluck('name')
->toArray();
Method 3: Using select() and $query->where() for each condition
A more efficient way to convert the SQL query is by using the select() method and $query->where() for each condition. Here’s how it can be done:
// Create a new DB instance
$db = DB::connection('default');
// Construct the query using select() and $query->where()
$twowaycompany = $db->table('company')
->select('*')
->join('merchantlink', 'merchantlink.initiator_user_id', '=', 'company.owner_user_id')
->join('merchantlinkrelation', 'merchantlinkrelation.merchantlink_id', '=', 'merchantlink.id')
->where($query = function ($query) {
$query->where('m.responder_user_id', '=', 86)
->orWhere('c.owner_user_id', '=', 86);
})
->whereRaw("mlr.ptype = 'dealer'")
->groupBy('c.id')
->pluck('name')
->toArray();
Best Practices
When converting SQL queries to Laravel query builder, keep the following best practices in mind:
- Use
join()instead of commas: In most cases, it’s better to use thejoin()method for combining tables rather than using commas. - Use
whereRaw()for complex conditions: When dealing with complex conditions that involve multiple operators or parentheses, usewhereRaw()for more readability and maintainability. - Group by necessary columns: Make sure to group your results by the required columns.
Conclusion
Converting SQL queries to Laravel query builder can be an intimidating task, especially when dealing with complex conditions. However, by following these methods and best practices, you should be able to effectively convert your SQL queries into equivalent Laravel queries.
Last modified on 2023-09-22