Laravel framework 06: files, migration filling, sessions, caching

Laravel framework 06: files, migration fill, session, cache

• 1. File upload
• • 1. File upload form
  • 2. Upload business processing
  • 3. All code
• 2. Migration and filling of data tables
• • 1. Migrating files
  • • ① Create a migration file
    • ② Write the migration file
    • ③ Execute the migration file
    • ④ Roll back the migration file
  • 2. Populate (seed) file
  • • ① Create a filling file
    • ② Write the filling file
    • ③ Execute the filling file
• 3. Session Control
• 4. Caching mechanism
• • 1. Set the cache
  • 2. Get the cache
  • 3. Delete the cache
  • 4. Counter

1. File upload

1. File upload form

• action, method, enctype
• file
• submit

<form action="/home/test/test12" method="POST" enctype="multipart/form-data">
    {<!-- -->{csrf_field()}}
    <input type="file" name="file" id="">
    <button type="submit">Submit</button>
</form>

2. Upload business processing

• Whether to upload files

$request->hasFile("avatar");

• Verify that the file was uploaded successfully

$request->file("avatar")->isValid();

• Get uploaded files

$file = $request->file("avatar");
// or
$file = $request->avatar;

• extension method
  • path: the absolute path of the file
  • extension: extension.
  • See the manual for more methods…
• Storage path
  If the path is for PHP code, it is recommended to use a relative path. If the path is for the browser, use an absolute path.
  You need to add the folder uploads under /public first.

$request->file("avatar")->move('./uploads', md5(time() . rand(100000, 999999)) .".". $request - > file("avatar") -> getClientOriginalExtension());

3. All code

public function test12(Request $request) {<!-- -->
    //Determine the request type
    if ($request->isMethod("POST")) {<!-- -->
        // upload
        if ($request->hasFile("avatar") & amp; & amp; $request->file("avatar")->isValid()) {<!-- -->
            $request->file("avatar")->move('./uploads', md5(time() . rand(100000, 999999)) .".". $request -> file( "avatar") -> getClientOriginalExtension());
        }
    }else{<!-- -->
        // show the view
        return view("home.test.test8");
    }
}

2. Data table migration and filling

• Migration: operation of creating data table + operation of deleting data table
• Filling: fill the data table with the data written into the test (data insertion operation)

1. Migrating files

• The files stored under database/migrations are called migration files.

① Create migration file

php .\artisan make:migration create_paper_table

• In the newly created migration file, up() is to create a data table, and down() is to delete a data table.

② Write migration file

• The Schema facade is used to manipulate the database.
• $table represents an instance of the entire table.
• Syntax: $table -> column type method (field name [, length/range]) -> column modification method ([modified value]);

public function up()
{<!-- -->
    Schema::create('paper', function (Blueprint $table) {<!-- -->
        $table->increments("id");
        $table->string("paper_name", 100);
        $table->tinyInteger("paper_score")->default(100);
        $table->integer("start_time")->nullable();
        $table->tinyInteger("duration");
        $table->enum("status", [1, 2])->default(1);
    });
}

public function down()
{<!-- -->
    Schema::dropIfExists('paper');
}

③ Execute the migration file

• Before executing the migration file for the first time, you need to create a migration file record table.

php .\artisan migrate:install

After execution, there will be an additional data table migrations in the database.

• Delete the built-in migration file and only keep your own.
• Execute the migration file

php .\artisan migrate

④ Rollback migration file

• Roll back the last migration operation

php .\artisan migrate:rollback

2. Populate (seed) file

• The files stored under database/seeds are called seed files.

① Create a fill file

php .\artisan make:seeder PaperTableSeeder

② Write a fill file

• In the form file you can use the DB facade to add data.

public function run() {<!-- -->
    //
    $data = [
        [
            "paper_name" => "Five-year college entrance examination, three-year simulation",
            "start_time" => strtotime(" + 7 days"),
            "duration" => "120",
        ],
        [
            "paper_name" => "Huanggang Secret Scroll",
            "start_time" => strtotime(" + 7 days"),
            "duration" => "120",
        ],
        [
            "paper_name" => "Hengshui mid-term volume",
            "start_time" => strtotime(" + 7 days"),
            "duration" => "120",
        ]
    ];
    DB::table()->insert($data);
}

③ Execute the filling file

php .\artisan db:seed --class=PaperTableSeeder

3. Session control

• Sessions are stored in files by default.
• Directory of session files: storage/framework/sessions.
• session facade: use Illuminate\Support\Facades\Session;
• session can also be used in views.

public function test13() {<!-- -->
    // Store a variable in the Session
    Session::put("name", "Zhang San");
    
    // Get the variables in the Session
    echo Session::get("name");
    
    // Get the variable in the Session, if it does not exist, return the default value
    echo Session::get("age", 80);
    echo Session::get("gender", function () {<!-- -->
        return "Walmart Shopping Bag";
    });
    
    // Get all relevant information in the Session
    var_dump(Session::all());
    
    // Check if the variable exists in the Session
    var_dump(Session::has("name"));
    
    // Delete variables in Session
    Session::forget("name");
    
    // Delete all variables in the Session
    Session::flush();
}

4. Caching mechanism

• The cache configuration is located in config/cache.php

1. Set cache

• put() If the key already exists, it will directly overwrite the original value.
• The validity period must be set, and the unit is minute.

Cache::put('key', 'value', $minutes);

• add() returns false if the key exists. If it does not exist, it will return true if it is successfully added.

Cache::add('key', 'value', $minutes);

• forever() is used for persistent storage to the cache, and must be deleted from the cache using the forget method.

Cache::forever('key', 'value');

• remember() If the key does not exist, get the default value and set the variable to the default value.

Cache::remember("time", 10, function (){<!-- -->
   return date("Y-m-d H:i:s");
});

2. Get cache

• get() Gets a variable.

Cache::get("name", "No username");
Cache::get("age", function (){<!-- -->
    return "No age is set";
});

• has() determines whether a variable exists

Cache::has("gender")

3. Delete cache

• pull() Get it from the cache and then delete it, which is often used for one-time storage.

Cache::pull("age")

• forget() Delete directly.

• flush() clears all caches and deletes the corresponding directory.

Cache::flush();

4. Counter

• increment and decrement are used to adjust integer values in the cache. Generally used for counters.

Cache::increment("count");
Cache::increment("count", 2);
Cache::decrement("count");
Cache::decrement("count", 2);