Error No Database Selected PHP/mySQL - php

I have read a bunch of the other posts about similar issues but I am very new to this so I am likely missing something. Most of the other questions I found were a lot more complicated than mine. I am trying to follow the w3schools tutorial for this and am testing locally using XAMPP. Right now I am just trying to get this to work successfully and eventually I am planning to submit data into a mySQL database from a web form.
<?php
$servername="localhost";
$dbname="mysql";
// Create connection
$conn = mysqli_connect($servername, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "INSERT INTO owner_table (ownerFirst, ownerLast, mobile)
VALUES ('John', 'Doe', '1111111111')";
if (mysqli_query($conn, $sql)) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);
?>
NOTE:
The connection is not failing from what I can tell. Removing everything after the first if statement, and adding else { echo "success" } outputs success. Again though, I am new to PHP.
If someone knows that the answer has been given in another post PLEASE PLEASE comment here and ill close this out.
http://www.w3schools.com/php/php_mysql_insert.asp

You should follow the proper syntax:
$conn = mysqli_connect(<host Name>, <username>, <password>, <database name>);
Reference: http://php.net/manual/en/function.mysqli-connect.php#refsect1-function.mysqli-connect-examples
Add two more parameters- username and password here:
$username = "root"; // Default values
$password = ""; // Default values
$conn = mysqli_connect($servername, $username, $password, $dbname);

Related

Processing my form with PHP is not working

on line 1 of my page i required the connection file before going on to write my code. at this point i think it is supposed to work but can not figure out why it didn't. please some one who knows better help me.
Can you help me with a sample PHP code for inserting data into mysql database using PHP, mysqli?
Thank you again in advance.
You can use this code for insert data to mysql DB using php and mysqli
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john#example.com')";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>

Recieve "HTTP ERROR 500" when attempting to create a database with php

I'm encountering an issue when I try to use php to create a database. I've google around, ensured that the user has permission to create a database and it still doesn't work.
I'm able to use PHP to create and modify tables once I create the database manually, but I'd like this code to run in PHP for personal reasons.
Here's the code, just in case I'm missing something.
*edit: grammar
<?php
$servername = "localhost";
$username = "user";
$password = "password";
// Create connection
$conn = new mysqli($servername, $username, $password);
// Check connection
if ($conn->connect_error){
die("Connection failed: " . $conn->connect_error);
}
//Create database
$sql = "CREATE DATABASE inkflow_backend";
if ($conn->query($sql) === TRUE){
echo "Database created successfully, continue.";
} else{
echo "Error creating database: " . $conn->error . "Please contact the developer or your network administrator.";
}
//Close connection
$conn->close();
?>
Review the quotes that you're using when printing a link to setup2.php.
They are causing a syntax error. Just putting a backslash before them would solve the problem:
<a href=\"setup2.php\" ...

When creating a database in MySQL with PHP using the following code where does we make the connection and where does we make the database?

I am new in PHP and would need some explanation. Here is a code where we connect to MySQL with PHP. Can you please explain me where is the statement that makes the connection? I can see only that we define what the value of $conn is, but does it mean execution as well? The other thing is: where do we create the database? I can see that we give the string "CREATE DATABASE myDB" as a value to $sql and we have an if statement, but does the expression ($conn->query($sql) === TRUE) also evaluated? It is strange for me, can somebody please explain it to me?! :) Thanks!
<?php
$servername = "localhost";
$username = "username";
$password = "password";
// Create connection
$conn = new mysqli($servername, $username, $password);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
// Create database
$sql = "CREATE DATABASE myDB";
if ($conn->query($sql) === TRUE) {
echo "Database created successfully";
} else {
echo "Error creating database: " . $conn->error;
}
$conn->close();
?>
Here is a simple explanation of which lines do what. If you would like to know specifically what the individual parts of these mean, then please say which ones so they can be further explained to you. Or the correct links pointed to.
I notice that you are using the W3Schools example, as an almost exact copy and paste. Have you installed MySQL on your machine and created a username and password?
<?php
$servername = "localhost"; // This is the location of your server running MySQL
$username = "username"; // This is the username for MySQL
$password = "password"; // This is the password for MySQL
// Create connection
$conn = new mysqli($servername, $username, $password); // This is where you create a connection
// Check connection
if ($conn->connect_error) { // This checks if the connection happened
die("Connection failed: " . $conn->connect_error); // and produces an error message if not
} // otherwise we move on
// Create database
$sql = "CREATE DATABASE myDB"; // This is the SQL query which is sent to the MySQL server
if ($conn->query($sql) === TRUE) { // When the if statement begins here, it executes the query and test if it returns true
echo "Database created successfully"; // If it returns true then here is the message is returns
}
else {
echo "Error creating database: " . $conn->error; // Or if there was error with the query this is returned
}
$conn->close(); // Close the connection when it is no longer in use
?>
Although, your question does not belong here (This place is to help with your coding issues), but I will give you a bit explanation.
PHP reads each line and EXECUTES It. the create connection part opens a new connection using the "new" object and save it a variable ($conn),
($conn->connect_error) checks if the connection was successful with connect_error property. if it was connected, continue, or else through and error and stop.
If connection was successful, then create the database based on connection opened in variable ($conn).

Building a custom function for CRUD

New to the concept of php custom function and was wondering how to build a custom function for INSERT
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john#example.com')";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
Can anyone help. Will appreciate if I can have link to a tutorial as well.
Here is a helpful tutorial for a begginer with Php. Hope this help:
http://alejoferguson.blogspot.com/2014/08/tutorial-php-mysql-recomendado_27.html
I would not recommend you to have server and password information on the same page your doing the query but rather to have it separately as is explained in this simple tutorial. ALso it provides you with the source code at the end of the tutorial.
Guide yourself by the images in this tutorial.

php store session variable in mysql database

I have a website in PHP. I try to store the session variable $_SESSION['user_name'] to a mysql database when a logged in user visits a specific webpage on my site.
<?php
$servername = "localhost";
$username = "user1";
$password = "user1";
$dbname = "payment";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = 'INSERT INTO users
VALUES ('.$_SESSION['user_name'].')';
if ($conn->query($sql) === TRUE) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
Error message:
Notice: Undefined variable: _SESSION in /opt/lampp/htdocs/succes.php on line 16
Tried a bunch of things but can't figure it out. What is wrong here?
You need to call session_start() at the beginning of your script (before using any $_SESSION variables). Also, you need quotes around the variable in you query:
$sql = 'INSERT INTO users
VALUES ("'.$_SESSION['user_name'].'")';
Please note that this is not safe; you are wide open to SQL injection. Instead, you should use prepared statements:
<?php
$servername = "localhost";
$username = "user1";
$password = "user1";
$dbname = "payment";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = 'INSERT INTO users
VALUES (?)';
$stmt = $conn->prepare($sql);
$stmt->bind_param('s', $_SESSION['user_name']);
if ($stmt->execute()) {
echo "New record created successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
Before you use any $_SESSION variables you need to call session_start().
Of topic a bit though, something to look into PDO. It can be a bit a tad slower than mysqli() however supports many more Database types. Here is a good article on Tuts+ explaining some of the differences as well as explaining essential security steps.
If I could be a bit biased I have created a PHP Class for PDO Connections which can be found on GitHub

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