php - mysqli - create database if does not exist [duplicate] - php

Question

This question already has answers here:
Turning query errors to Exceptions in MySQLi [duplicate]
(3 answers)
Closed 1 year ago.
I am using PHP and mysqli and trying to create the DB if it does not exist in my dbLogin file. Seems like it should be a fairly simple thing to do. It seems to be getting hung up on the first creation attempt with an error and won't move past or catch the error.
Here is my very simple code:
<?php
$con = '';
try {
$con = new mysqli("host", "user", "pass", "db");
}
catch(Exception $e) {
echo "Error: $e<br />";
$con = new mysqli("host", "user", "pass");
$con->query("CREATE DATABASE IF NOT EXISTS db;");
}
/* check connection */
if ($con->connect_errno) {
printf("Connect failed: %s\n", $con->connect_error);
exit();
}
?>
Now, when I run the code above, all I get is the following error:
Warning: mysqli::__construct(): (HY000/1049): Unknown database
'db' in xyz\DBLogin.php on line 6 Connect
failed: Unknown database 'db'
Line 6 is the line inside the try block. It does not create the database and does not move past the error.

Answer 1

Your problem is that mysqli::__construct only generates a warning if it can't connect to the database, and you can't directly catch a warning. Now you can workaround that (for example, see this question) but it's probably simpler to do something like this:
$con = new mysqli("host", "user", "pass");
if ($con->connect_errno) {
printf("Connect failed: %s\n", $con->connect_error);
exit();
}
if (!$con->select_db('db')) {
echo "Couldn't select database: " . $con->error;
if (!$con->query("CREATE DATABASE IF NOT EXISTS db;")) {
echo "Couldn't create database: " . $con->error;
}
$con->select_db('db');
}

Answer 2

//check if the database exist - PHP
$cons = '';
$cons = new mysqli("host", "user", "pass");
$okk = mysqli_query($cons, "SHOW DATABASES LIKE 'db'");
$okkno = mysqli_num_rows($okk);
if($okkno <=0){
$fanya = mysqli_query($cons, "CREATE DATABASE IF NOT EXISTS db;");
echo "Database created successifully";
}