Laravel is a web application development framework based on PHP. Its powerful and flexible features are increasingly sought after by developers. When using Laravel to develop projects, it is a very common requirement to perform CRUD operations on the database. This article will introduce how to use Laravel to add, delete, modify and query database tables.
1. Connect to the database
In Laravel, connecting to the database requires modifying the .env
file. In this file, we can define the database connection method, user name, password, database name and other information. The following is an example of a .env
file:
DB_CONNECTION=mysql DB_HOST=127.0.0.1 DB_PORT=3306 DB_DATABASE=laravel DB_USERNAME=root DB_PASSWORD=
Among them, DB_CONNECTION
represents the database type used, which can be mysql
, sqlite
, pgsql
, etc. DB_HOST
represents the host address of the database, DB_PORT
represents the port number of the database, DB_DATABASE
represents the name of the database, DB_USERNAME
represents the user who connects to the database Name, DB_PASSWORD
represents the password to connect to the database.
2. Create a data table
In Laravel, you can use the artisan make:model
command to create a model corresponding to the database table. Before generating the model file, we need to define the structure of the database table. In Laravel, you can use migration files to define the database table structure.
In the root directory of the Laravel project, use the following command to create a migration file named create_users_table
:
php artisan make:migration create_users_table --create=users
where create_users_table
is the migration file The name, --create=users
means that we want to create a data table named users
.
Modify the generated migration file and define the database table structure in the up
method. For example, if we want to create a table named users
, containing three fields: name
, email
and password
, then we can do it as follows Define in the following way:
public function up() { Schema::create('users', function (Blueprint $table) { $table->id(); $table->string('name'); $table->string('email')->unique(); $table->string('password'); $table->timestamps(); }); }
After defining the migration file, execute the following command to apply the migration file to the database:
php artisan migrate
After successful execution, you can see the newly created Data sheet.
3. Add data
In Laravel, you can add, delete, modify and query database tables through the Eloquent
model. In the previous step, we have created the User
model. You can create a new user in the following way:
$user = new User; $user->name = 'john'; $user->email = 'john@example.com'; $user->password = Hash::make('password'); $user->save();
First create a new User
model object , then set the attributes of the model (that is, the fields of the data table), and finally call the save
method to save the data to the database.
In addition, you can also use the create
method to create and save model instances at one time:
$user = User::create([ 'name' => 'jane', 'email' => 'jane@example.com', 'password' => Hash::make('password') ]);
4. Query data
In Laravel, you can Use the Eloquent
model to perform query operations on database tables. The following are some common query methods:
$users = User::all();
$user = User::find(1);
$users = User::where('name', 'john')->get();
$users = User::where('name', 'like', 'j%') ->orderBy('name', 'desc') ->take(10) ->get();
In use When using advanced query methods, multiple query conditions can be chained to filter out model instances that meet the requirements.
5. Modify data
In Laravel, you can update the data in the database table by modifying the attributes of the model instance. For example, to change the email address of the user record name
to john
to john@example.org
, you can proceed as follows:
$user = User::where('name', 'john')->first(); $user->email = 'john@example.org'; $user->save();
Or use the update
method to perform batch update operations:
User::where('name', 'john')->update(['email' => 'john@example.org']);
6. Delete data
In Laravel, you can use the Eloquent
model to do it Database table deletion operation. To delete a specified model instance, you can use the following method:
$user = User::find(1); $user->delete();
or use the destroy
method to delete multiple model instances in batches:
User::where('name', 'john')->delete();
The above is using Laravel for database Basic knowledge of table addition, deletion, modification and query operations. Laravel has powerful ORM functions that can help developers perform database operations more efficiently.
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