Reputation: 1482
How to update a status from database if status is empty in using php? I have this condition in php. I have this if condition that decides if $getstatus
is empty it will update from database to Avail
. I tried refreshing the page after querying the database. But it will not update in database. Is there anyway to update this without using form submit in php?
<?php
session_start();
include "includes/connection.php";
// Display all parking slots
$sql = $connection->prepare('SELECT * FROM parkingslot where parkingslotid = 1');
$sql->execute(); // execute query
$result = $sql->get_result(); // fetch result
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
$getstatus = $row["status"];
echo $getstatus;
}
}
if (empty($getstatus)) {
$sql = $connection->prepare("UPDATE parkingslot SET status = 'Avail' where parkingslotid = 1 ");
}
?>
Codes in connection for connecting to database
connection.php
<?php
$server = "localhost";
$username = "root";
$password = "";
// create connection
$connection = mysqli_connect($server,$username,$password);
// check connection
if(!$connection)
{
die("No connection found." . mysqli_connect_error());
}
else {
// select a database
$select_db = mysqli_select_db($connection,'smartparkingsystem');
if(!$select_db)
{
$sql = 'CREATE DATABASE sample';
// create database if no db found
if(mysqli_query($connection,$sql)) {
echo "Database Created";
}
else {
echo "Database not found" . mysqli_connect_error() . '\n';
}
}
else {
// Database already existed
// do nothing...
}
}
?>
Upvotes: 0
Views: 483
Reputation: 364
If I understand your goal of: For row(s) whereparkingslotid
=1
- Update status
to 'Avail' but only if status
is not currently set, this might help:
<?php
session_start();
include "includes/connection.php";
$connection->prepare("UPDATE `parkingslot` SET `status`=? WHERE `parkingslotid`=? AND (`status` IS NULL OR `status`=?)");
$connection->bind_param("sis", $status, $parkingslotid, $empty_str);
$status = 'Avail';
$parkingslotid = 1;
$empty_str = '';
$connection->execute();
echo $connection->affected_rows.' rows affected';
$connection->close();
?>
This saves a bit of processing by not checking with PHP first.
Upvotes: 1
Reputation: 162
Edited:
@lumonald gave the right anwser in the comment. You're not executing your second SQL statement.
Upvotes: 1
Reputation: 336
You can use this query:
"UPDATE parkingslot SET status = 'Avail' where status IS NULL OR status = '' "
Upvotes: 1