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CREATE TABLE <code>mydbname</code>.<code>content</code> ( <code>ID</code> INT(11) NOT NULL AUTO_INCREMENT , <code>title</code> VARCHAR(100) NOT NULL , <code>content</code> LONGTEXT NOT NULL , <code>author</code> VARCHAR(50) NOT NULL , PRIMARY KEY (<code>ID</code>)) ENGINE = MyISAM COMMENT = 'content table';
conn.php
file in your root/includes folder.conn.php
file, remember to include your own database credentials.
<?php
$letsconnect = new mysqli("localhost","dbuser","dbpass","dbname");
?>
index.php
at the root of your CMS folder.
<?php
include('includes/conn.php');
if ($letsconnect -> connect_errno) { echo "Error " . $letsconnect -> connect_error;
}else{
$getmydata=$letsconnect -> query("SELECT * FROM content");
foreach($getmydata as $mydata){ echo "Title: "; echo $mydata['title']; echo "<br/>"; echo "Content: "; echo $mydata['content']; echo "<br/>"; echo "Author: "; echo $mydata['author']; echo "<br/>"; echo "<br/>";
}
}
$letsconnect -> close();
?>
index.php
in your backend folder.
<html>
<head><title>Backend - Capture Content</title></head>
<body>
<form action="<?php $_SERVER[‘PHP_SELF’];?>" method="post">
<input type="text" name="title" placeholder="Content Title here" required/>
<textarea name="content">Content Here</textarea>
<input type="text" name="author" placeholder="Author" required/>
<input type="submit" value="Save My Data" name="savedata"/>
</form>
</body>
</html>
<form>
tag.
<?php
if(isset($_POST['savedata'])){
include('../includes/conn.php');
if ($letsconnect->connect_error) {
die("Your Connection failed: " . $letsconnect->connect_error);
}else{
$sql = "INSERT INTO content(title,content,author)VALUES ('".$_POST["title"]."', '".$_POST["content"]."', '".$_POST["author"]."')";
if (mysqli_query($letsconnect, $sql)) {
echo "Your data was saved successfully!";
} else { echo "Error: " . $sql . "" . mysqli_error($letsconnect);
} $letsconnect->close();
}
}
?>
Note, this is a basic MySQL query to insert data. However, before using this in production it's important to add proper escaping and security to prevent SQL injections. This will be covered in the next article.
WebSockets have compatibility with 96.5% of clients globally
OnConnection
method.OnOpen
gets called when a new connection is made.OnClose
gets called when a client quits. It's essential to keep an eye on memory management, and essential to keep tidying up as you move through the code.OnError
gets called when there is an exception faced by the user.OnMessage
gives the text of the JSON message, which is being exchanged with the client.Me: Is that really important that the tables are MyISAM? It's 2018, you know.. There are dozens of queries in queue waiting for table-level locks.
R**: Are they MyISAM? Really?
Me: Yes.. Any objection against converting them to InnoDB? With the current state of the website, with all those tons of Gateway Timeouts, it's not going to make it worse if I do it right now..
Me: Nah, it didn't help a lot.. But, looking at the SHOW PROCESSLIST output, I see something weird. What, do you think, this query does? SELECT LAST_INSERT_ID() FROM images?
R**: ehh... Gets you the last AUTO_INCREMENT id from images table?
Me: Let's play another good news bad news joke.. Good news: you're right, it gets you the last AUTO_INCREMENT id. Bad news: it's not for table, it's for the session. Worse news: this query gets you the last AUTO_INCREMENT id and does it exactly as many times as there are rows in the images table. how many are there?
R**: about 8mln. #@%&! It's sending 8mln rows on every image upload, through the network!
Me: Bingo! 8mln rows, with one and the same integer value in all of them.
R**: Ouch... Aaaand... Before today, it was not an issue. Because the database was on the same server as the application..
Me: Exactly, it used the loopback interface, and now it's using ehternet, which, apparently, doesn't have a super good bandwidth. We don't have a gigabit channel between servers, do we?
R**: No, it's 100 Mbit
Me: Are you fixing the query, BTW?
R**: yeah, man, deploying it...
hasManyThrough()
for the relation Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->string('email')->unique();
$table->string('password');
$table->integer('country_id')->unsigned();
$table->rememberToken();
$table->timestamps();
$table->foreign('country_id')->references('id')->on('countries')
->onDelete('cascade');
});
Schema::create('posts', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->integer('user_id')->unsigned();
$table->timestamps();
$table->foreign('user_id')->references('id')->on('users')
->onDelete('cascade');
});
Schema::create('countries', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
$table->timestamps();
});
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Country extends Model
{
public function posts(){
return $this->hasManyThrough(
Post::class,
User::class,
'country_id',
'user_id',
'id',
'id'
);
}
}
$country = Country::find(1);
dd($country->posts);
morphMany()
and morphTo()
for relation.Schema::create('posts', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->timestamps();
});
Videos TableSchema::create('videos', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->timestamps();
});
Comments TableSchema::create('comments', function (Blueprint $table) {
$table->increments('id');
$table->string("body");
$table->integer('commentable_id');
$table->string("commentable_type");
$table->timestamps();
});
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Post extends Model
{
public function comments(){
return $this->morphMany(Comment::class, 'commentable');
}
}
Video Model<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Video extends Model{
public function comments(){
return $this->morphMany(Comment::class, 'commentable');
}
}
Comment Model<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Comment extends Model{
public function commentable(){
return $this->morphTo();
}
}
$post = Post::find(1);
$comment = new Comment;
$comment->body = "Hi Harikrishnan";
$post->comments()->save($comment);
$video = Video::find(1);
$comment = new Comment;
$comment->body = "Hi Harikrishnan";
$video->comments()->save($comment);
$post = Post::find(1);
dd($post->comments);
$video = Video::find(1);
dd($video->comments);
morphToMany()
and morphedByMany()
will be used for many to many polymorphic relationshipsSchema::create('posts', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->timestamps();
});
Videos TableSchema::create('videos', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->timestamps();
});
Tags tableSchema::create('tags', function (Blueprint $table) {
$table->increments('id');
$table->string("name");
$table->timestamps();
});
Taggables tableSchema::create('taggables', function (Blueprint $table) {
$table->integer("tag_id");
$table->integer("taggable_id");
$table->string("taggable_type");
});
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Post extends Model
{
public function tags(){
return $this->morphToMany(Tag::class, 'taggable');
}
}
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Video extends Model
{
public function tags(){
return $this->morphToMany(Tag::class, 'taggable');
}
}
Tag Model<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Tag extends Model
{
public function posts(){
return $this->morphedByMany(Post::class, 'taggable');
}
public function videos(){
return $this->morphedByMany(Video::class, 'taggable');
}
}
Creating Records$post = Post::find(1);
$tag = new Tag;
$tag->name = "Hi Harikrishnan";
$post->tags()->save($tag);
$video = Video::find(1);
$tag = new Tag;
$tag->name = "Vishnu";
$video->tags()->save($tag);
$post = Post::find(1);
$tag1 = new Tag;
$tag1->name = "Kerala Blasters";
$tag2 = new Tag;
$tag2->name = "Manajapadda";
$post->tags()->saveMany([$tag1, $tag2]);
$video = Video::find(1);
$tag1 = new Tag;
$tag1->name = "Kerala Blasters";
$tag2 = new Tag;
$tag2->name = "Manajappada";
$video->tags()->saveMany([$tag1, $tag2]);
$post = Post::find(1);
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$post->tags()->attach([$tag1->id, $tag2->id]);
$video = Video::find(1);
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$video->tags()->attach([$tag1->id, $tag2->id]);
$post = Post::find(1);
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$post->tags()->sync([$tag1->id, $tag2->id]);
$video = Video::find(1);
$tag1 = Tag::find(3);
$tag2 = Tag::find(4);
$video->tags()->sync([$tag1->id, $tag2->id]);
$post = Post::find(1);
dd($post->tags);
$video = Video::find(1);
dd($video->tags)
$tag = Tag::find(1);
dd($tag->posts);
$tag = Tag::find(1);
dd($tag->videos);