Laravel is a popular PHP framework that allows developers to quickly build efficient, scalable web applications. It's common to use SQL queries in Laravel when you need to query data from a database. This article will introduce how to execute SQL queries in Laravel.
Preparation
Before starting to use Laravel to execute SQL queries, we need to configure the database connection information first. In Laravel, configuring database connection information is very simple. You only need to open the .env
file and modify the following information:
DB_CONNECTION=mysql DB_HOST=127.0.0.1 DB_PORT=3306 DB_DATABASE=database_name DB_USERNAME=username DB_PASSWORD=password
We only need to modify these parameters, and Laravel will automatically connect to our database and connect using the parameters we provide. Now, we are ready to start executing SQL queries.
Executing queries
There are several ways to execute SQL queries in Laravel. Here are some commonly used methods.
Using the DB class
Laravel's DB class provides a series of methods that can be used to execute SQL queries. First, we need to introduce the DB class in our controller or model:
use IlluminateSupportFacadesDB;
Once we have introduced the DB class, we can use the following methods to execute SQL queries.
Query
The select()
method of the DB class can be used to query data. Here is an example:
$data = DB::select('SELECT * FROM users');
In the above example, we query all the data in the users
table and store the results in the $data
variable. You can also use parameters to build queries dynamically:
$id = 1; $data = DB::select('SELECT * FROM users WHERE id = ?', [$id]);
In the above example, we used a placeholder ?
to represent the $id
parameter position and then pass that parameter to the second parameter of the select()
method.
Insert
The insert()
method of the DB class can be used to insert data. The following is an example:
$name = 'John Doe'; $email = 'johndoe@example.com'; DB::insert('INSERT INTO users (name, email) VALUES (?, ?)', [$name, $email]);
In the above example, we inserted a piece of data into the users
table.
Update
The update()
method of the DB class can be used to update data. The following is an example:
$id = 1; $email = 'johndoe@example.com'; DB::update('UPDATE users SET email = ? WHERE id = ?', [$email, $id]);
In the above example, we update the email attribute of the user with id 1 in the users
table to johndoe@example.com
.
Delete
The delete()
method of the DB class can be used to delete data. The following is an example:
$id = 1; DB::delete('DELETE FROM users WHERE id = ?', [$id]);
In the above example, we delete the user with id 1 in the users
table.
Using Query Builder
Laravel provides another way to execute SQL queries, namely Query Builder. Query Builder is a chained query syntax that can be used to build complex query statements.
Query
The following is an example of querying data using Query Builder:
$data = DB::table('users')->get();
In the above example, we query all the data in the users
table data and store the results in the $data
variable. You can also use chaining methods to build queries dynamically:
$data = DB::table('users') ->select('name', 'email') ->where('id', '=', 1) ->get();
In the above example, we use the select()
method to select columns in the query results, using where( )
method adds a WHERE clause.
Insert
The following is an example of inserting data using Query Builder:
$name = 'John Doe'; $email = 'johndoe@example.com'; DB::table('users')->insert([ 'name' => $name, 'email' => $email ]);
In the above example, we inserted a row into the users
table data.
Update
The following is an example of updating data using Query Builder:
$email = 'johndoe@example.com'; DB::table('users') ->where('id', 1) ->update(['email' => $email]);
In the above example, we will users
The id is 1 in the table The user's email attribute is updated to johndoe@example.com
.
Delete
The following is an example of deleting data using Query Builder:
DB::table('users')->where('id', 1)->delete();
In the above example, we will users
The id is 1 in the table user deleted.
Summary
In this article, we introduced how to execute SQL queries in Laravel. Using DB classes or Query Builder we can easily query, insert, update and delete data. Using these features of Laravel allows us to build web applications more efficiently and reliably.
The above is the detailed content of laravel query via sql. For more information, please follow other related articles on the PHP Chinese website!

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