PHP MYSQL TO JSON

https://www.opentechguides.com/how-to/article/php/100/mysql-to-json.html

<?php

// Initialize variable for database credentials
$dbhost = 'hostname';
$dbuser = 'username';
$dbpass = 'password';
$dbname = 'sakila';

//Create database connection
  $dblink = new mysqli($dbhost, $dbuser, $dbpass, $dbname);

//Check connection was successful
  if ($dblink->connect_errno) {
     printf("Failed to connect to database");
     exit();
  }

//Fetch 3 rows from actor table
  $result = $dblink->query("SELECT * FROM actor LIMIT 3");

//Initialize array variable
  $dbdata = array();

//Fetch into associative array
  while ( $row = $result->fetch_assoc())  {
	$dbdata[]=$row;
  }

//Print array in JSON format
 echo json_encode($dbdata);
 
?>

Result:

[
	{
	"actor_id":"1",
	"first_name":"PENELOPE",
	"last_name":"GUINESS",
	"last_update":"2006-02-15 04:34:33"
	},
	{	
	"actor_id":"2",
	"first_name":"NICK",
	"last_name":"WAHLBERG",
	"last_update":"2006-02-15 04:34:33"
	},
	{
	"actor_id":"3",
	"first_name":"ED",
	"last_name":"CHASE",
	"last_update":"2006-02-15 04:34:33"
	}
]

As you can see, the result is a valid JSON. You may use this in combination with Jquery/AJAX to pass database data to a web application that expects data in JSON.

CONNECT USING MYSQLI WITH EXAMPLE

 <?php

/* Attempt MySQL server connection. Assuming you are running MySQL server with default setting (user 'root' with no password) */ $link = mysqli_connect("localhost", "root", "", "demo"); // Check connection if($link === false){ die("ERROR: Could not connect. " . mysqli_connect_error()); } // Attempt select query execution $sql = "SELECT * FROM persons"; if($result = mysqli_query($link, $sql)){ if(mysqli_num_rows($result) > 0){ echo "<table>"; echo "<tr>"; echo "<th>id</th>"; echo "<th>first_name</th>"; echo "<th>last_name</th>"; echo "<th>email</th>"; echo "</tr>"; while($row = mysqli_fetch_array($result)){ echo "<tr>"; echo "<td>" . $row['id'] . "</td>"; echo "<td>" . $row['first_name'] . "</td>"; echo "<td>" . $row['last_name'] . "</td>"; echo "<td>" . $row['email'] . "</td>"; echo "</tr>"; } echo "</table>"; // Free result set mysqli_free_result($result); } else{ echo "No records matching your query were found."; } } else{ echo "ERROR: Could not able to execute $sql. " . mysqli_error($link); } // Close connection mysqli_close($link); ?>

https://www.tutorialrepublic.com/php-tutorial/php-mysql-select-query.php

Reset Wordpress 'next User ID' number

 First go into the wp_users table and delete any users you need to.

Then go into the wp_usermeta table and delete any meta entries that correspond do the IDs of those deleted users.

Then you need to alter the wp_users table to reset its auto increment value. So you can do that in phpMyAdmin, or use SQL like this:

ALTER TABLE `wp_users` AUTO_INCREMENT={ID you want to be used next}

So if you want the next created user to have the id number 4 it would look like this:

ALTER TABLE `wp_users` AUTO_INCREMENT=4

share  edit   

Echo won't render data from Wordpress Mysql

When I used this code, the result/echo display as I wanted.

<?php
$user_checks = $wpdb->get_results( 
    "
    SELECT ID, user_nicename
    FROM $wpdb->users
    "
);

foreach ( $user_checks as $user_check ) 
{
    echo $user_check->ID;
    echo $user_check->user_nicename;
}
?>

But when I choose table other then what wordpress provide e.g:

<?php
    $user_checks = $wpdb->get_results( 
        "
        SELECT id, name
        FROM $wpdb->uap_banners
        "
    );

    foreach ( $user_checks as $user_check ) 
    {
    echo $user_check->id;   
    echo $user_check->name;
    }
    ?>

The Result is blank...

I ask Wordpress community to help me

https://wordpress.stackexchange.com/questions/370534/when-wordpress-default-table-echo-success-when-plugin-table-echo-blank

and I got feedback from 

Jacob Peattie

he said

$wpdb does not contain any reference to custom tables. So the uap_banners property doesn't exist. You need to write in the table name the say way it was written when creating the table. So in your case that would probably be (assuming you included the database prefix):

$user_checks = $wpdb->get_results( 
    "
    SELECT id, name
    FROM {$wpdb->prefix}uap_banners
    "
);

The problem solved