Why it's not "if" and not "else"? - php

I have this code:
$link = mysql_connect("localhost", "ctmanager", "pswsafgcsadfgG");
if ( ! $link )
die("I cannot connect to MySQL.<br>\n");
else
print "Connection is established.<br>\n";
print "a";
if ( mysql_create_db("ct", $link) )
print "AAA";
else
print "BBB";
print "2";
die();
And this is the output:
Connection is established.
a
So, I cannot understand how it's possible that neither "AAA" no "BBB" is outputted. Is it because program dies at mysql_create_db?

You probably guessed right. Try adding:
error_reporting(-1);
ini_set('display_errors', 'On');
at the very top of your script. You will get more details I'm sure. Post your findings and I'll update my answer if needed to.
Also, if you use PHP 5, you can try:
try
{
if (mysql_create_db("ct", $link))
echo 'AAA';
else
echo 'BBB';
}
catch (Exception $e)
{
echo 'Caught exception: ', $e->getMessage(), "\n";
}
maybe this will catch something...
Also, as František Žiačik pointed out with his link:
The function mysql_create_db() is
deprecated. It is preferable to use
mysql_query() to issue an sql CREATE
DATABASE statement instead.

mysql_create_db is deprecated in PHP5, maybe there even does not exist anymore.
See http://php.net/manual/en/function.mysql-create-db.php for an example how to do it.

I think you're right it is failing at mysql_create_db but i would guess it's the SQL that you're passing into it. are you trying to create a DB called "ct"? If so i'd try "CREATE DATABASE ct"

What PHP version are you running? According to the documentation, mysql_create_db is depracated, and a CREATE DATABASE query should be issued instead.
if (mysql_query("CREATE DATABASE ct", $link))
print "AAA";
else
print "BBB";

I think this would be the alternate way hopefully.
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
$sql = 'CREATE DATABASE my_db';
if (mysql_query($sql, $link)) {
echo "Database my_db created successfully\n";
} else {
echo 'Error creating database: ' . mysql_error() . "\n";
}
?>

Related

Connection to db using php in localhost

Even if I have used LAMPP many times, this time something goes wrong. When I visit the browser(chrome) nothing echos. Here is my code:
index.php
<?php
error_reporting(E_ALL); /*after edit*/
$link = mysqli_connect('localhost', 'root', 'root', 'db');
if (!$link) {
die('Could not connect: ' . mysqli_error());
}
echo 'Connected successfully';
mysqli_close($link);
?>
Do I miss something? The output is nothing. By the way i write my files in
var/www/html/my_pages
and i call it this way: localhost/my_pages. Simple echos are working and php in general is fine. Something goes wrong with my db connection.
Use this code
<?php
$link = mysqli_connect('localhost', 'root', 'root', 'db');
if (!$link) {
die('Could not connect: ' . mysqli_error());
}
else
{
echo 'Connected successfully';
}
?>
Yes probably, because mysqli_connect() method return the object, not Boolean value.
You can verify the connection with the following code:
if($link->connect_error)
die('Connect Error (' . mysqli_connect_errno() . ') '. mysqli_connect_error());
return false;
}
else{
echo "Connection Successful";
return $link;
}
Why not using PDO.
$dsn = "mysql:host=localhost;dbname=db";
try {
$pdo = new PDO($dsn, "root", "");
} catch (PDOException $ex) {
$ex->getMessage();
}
with PDO you can change anytime you need the Db vendor:
http://php.net/manual/en/book.pdo.php
<?php
echo phpinfo();
?>
Run this file and get all PHP and apache details. Search for mysqli support in it. If it is supported, you should have something like below.
Also check for your root directory
Thanks everyone for the response! I found the problem. Something went wrong and mysqli wasn't enabled in php. That's why i had this error Fatal Error:Call to undefined function mysqli_connect() in /var/www/html/diamond/index.php on line 8 I reinstalled php and problem solved :)

Connecting to MYSQL using php

I am trying to connect to MYSQL using php, but when I use the following command:
$link=mysql_connect("localhost","root","password");
and echo $link, it gives me Resource id #98. What does this mean? Am I not connected?
Okay, I guess it sounds like the connection is okay. Now, with the following code, I am not seeing any changes in the mysql database. Why could that be?
<?php
$conn=new mysqli("localhost","root","password","database");
$sql="INSERT INTO chat_active (user, time)
VALUES('John', '1234')";
?>
What makes you think you are not connected?
According to the docs, mysql_connect()
[r]eturns a MySQL link identifier on success or FALSE on failure.
Since it did not return FALSE, but rather a resource identifier, that means the connection was successful.
Also note that the mysql extension is deprecated since PHP 5.5.0 as MortimerCat pointed out. Instead you should look into the MySQLi or the PDO extension.
"Now, with the following code, I am not seeing any changes in the mysql database. Why could that be?"
As per your edit which you are now using mysqli_ to connect with, and that you're saying that you're not seeing any changes in your database, is because:
You're not passing the DB connection to your query and it is required when using mysqli_.
Rewrite, with a few more goodies:
<?php
$conn=new mysqli("localhost","root","password","database");
// Check if you've any errors when trying to access DB
if ($conn->connect_errno) {
printf("Connect failed: %s\n", $conn->connect_error);
exit();
}
$sql="INSERT INTO chat_active (user, time) VALUES ('John', '1234')";
$result = $conn->query($sql);
// Check if you've any errors when trying to enter data in DB
if (!$result)
{
throw new Exception($conn->error);
}
else{
echo "Success";
}
Read the manual http://php.net/manual/en/mysqli.query.php
Once you've grasped that, get to know mysqli with prepared statements, or PDO with prepared statements, they're much safer.
References:
http://php.net/manual/en/book.mysqli.php
http://php.net/manual/en/mysqli.query.php
http://php.net/manual/en/mysqli.error.php
http://php.net/manual/en/language.exceptions.php
Footnotes:
Your column names user, time suggests that you're trying to enter a string and what appears to be and to be intended as "time" and that the user column is set to varchar.
Make sure that you haven't setup your time column other than a datetime-related type, otherwise MySQL may complain about that.
MySQL stores dates as YYYY-mm-dd as an example.
Visit https://dev.mysql.com/doc/refman/5.0/en/datetime.html in regards to different date/time functions you can use.
MySQL references:
https://dev.mysql.com/doc/refman/5.0/en/char.html
https://dev.mysql.com/doc/refman/5.0/en/data-types.html
https://dev.mysql.com/doc/refman/5.0/en/datetime.html
You yould use mysqli or PDO.
Here's a connection example with PDO:
<?php
$dbuser = 'user';
$dbpasswd = 'passwd';
$dbname = 'dbname';
try {
$gbd = new PDO("mysql:host=localhost;dbname=$dbname;charset=utf8", $dbuser, $dbpasswd);
$gbd->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e) {
echo $e->getMessage();
}
PDO CRUD examples:
//INSERT
try {
$sentence = $gbd->prepare("INSERT INTO table (param1, param2) VALUES (:param1, :param2)");
$sentence->bindParam(':param1', $param1);
$sentence->bindParam(':param2', $param2);
$sentence->execute();
}
catch (PDOException $e) {
echo 'Query failed: ' . $e->getMessage();
}
//SELECT
try {
$sentence = $gbd->prepare("SELECT param1,param2 FROM table WHERE param1 = :param1 AND param2 = :param2)");
$sentence->bindParam(':param1', $param1);
$sentence->bindParam(':param2', $param2);
$sentence->execute();
while ($row = $sentence->fetch(PDO::FETCH_ASSOC)){ //Also available FETCH_NUM,FETCH_BOTH AND OTHERS
$result['param1'] = $row['param1'];
$result['param2'] = $row['param2'];
}
}
catch (PDOException $e) {
echo 'Query failed: ' . $e->getMessage();
}
//UPDATE
try {
$sentence = $gbd->prepare("UPDATE table SET param1 = :param1, param2 = :param2)");
$sentence->bindParam(':param1', $param1);
$sentence->bindParam(':param2', $param2);
$sentence->execute();
}
catch (PDOException $e) {
echo 'Query failed: ' . $e->getMessage();
}
//DELETE
try {
$sentence = $gbd->prepare("DELETE table WHERE param1 = :param1 AND param2 = :param2)");
$sentence->bindParam(':param1', $param1);
$sentence->bindParam(':param2', $param2);
$sentence->execute();
}
catch (PDOException $e) {
echo 'Query failed: ' . $e->getMessage();
}
And here's PDO manual
http://php.net/manual/en/book.pdo.php
u are not executing that query.u are only declaring that query.
for execution do--
$conn->query($qry);
it will,execute ur query.

Why is my PDO not working?

I am starting to use PDO and I successfully connected to MySQL using PDO. However, when I try to SELECT stuff from my DB, nothing happens. Nothing is echoed. (even though I have records in that table, and the column username exists) No error in my PHP log.
I am using MAMP and all PDO components seem to be working in phpinfo() (since I was able to connect to db in the first place)
Please let me know what could have gone wrong. Thanks a lot
<?php
try
{
$connection = new PDO('mysql:host=localhost;dbname:my_db','my_username',
'xxxxxxx');
$stmt=$connection->prepare("SELECT * FROM users");
$stmt->execute();
while ($row=$stmt->fetch(PDO::FETCH_OBJ)){
echo $row->username;
}
}
catch(Exception $e)
{
echo "There was an error connecting to the database";
}
?>
You need to tell PDO that you want it to throw exceptions:
$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
Following your comment below, it is apparent that your DSN is incorrect. It should be:
$connection = new PDO('mysql:host=localhost;dbname=my_db','my_username','xxxxxxx');
Note that the syntax is dbname= rather than dbname: (which you had originally).
First, get your query out of your PDO connection segment...
<?php
try
{
$connection = new PDO('mysql:host=localhost;dbname:my_db','my_username',
'xxxxxxx');
}
catch(Exception $e)
{
echo "There was an error connecting to the database";
}
?>
Then, do it.
<?php
$SQL = 'SELECT * FROM users';
foreach($connection->query($SQL) as $row){
print $row['username'] . "\n".'<br />';
}
?>
Why not ask PHP?
catch(Exception $e)
{
die($e);
}
Looks like your either don't have data in that table or have an error:
Try to add this code after $stmt->execute();:
$arr = $sth->errorInfo();
print_r($arr);

PHP PDO error successful no matter what

I have a problem with my database! Here is my code:
<?php
$host = "/homes/49/jc192699/public_html/dbase";
$database = "EduPro.db";
$dbhandle = new PDO("sqlite:".$host.$database);
if (!$dbhandle){
echo "Error connecting to database.\n";
}
else{
echo "<br>";
echo "<br>";
echo "Database connection successful!";
}
mysql_select_db($database);
?>
The problem is that it's saying "Database connection successful!" No matter what I do, if I type the address in wrong, it still says successful, when I renamed the database to a database that doesn't exist, it still says successful. I can't see what the problem is here?
If anybody could help me out it would be GREATLY appreciated!
Thank you!
For starters, the PDO constructor throws an exception if there is an error. It does not return false. Check for errors using
try {
$dbhandle = new PDO("sqlite:".$host.$database);
} catch (PDOException $e) {
echo 'Connection failed: ' . $e->getMessage();
}
Secondly, as you are using SQLite, provided your dbase directory is writeable by the script, your connection attempt will create an empty database.
Try this:
<?php
try {
/*** connect to SQLite database ***/
$dbh = new PDO("sqlite:/path/to/database.sdb");
}
catch(PDOException $e)
{
/*** real error message prints here ***/
echo $e->getMessage();
}
?>
This is directly taken from here:
http://www.phpro.org/tutorials/Introduction-to-PHP-PDO.html#4.2

php my_sql connection problem

I have a problem trying to connect to a my_sql database. I'm very new to PHP, so this is probably a very simple problem. At the top of my index.php I have the following code:
try
{
echo 'here 1';
$db=mysql_connect('localhost', 'root', 'password') or die(mysql_error());
echo 'here 2';
if(!$db)
{
echo 'here 3';
}
$db_selected=mysql_select_db("alphaes", $db);
echo 'here 4';
if (!$db_selected) {
die ('Can\'t use foo : ' . mysql_error());
}
echo 'here 5';
}
catch (Exception $e)
{
echo 'Caught exception: ', $e->getMessage(), "\n";
}
The problem is that the only output from the page is 'here 1'. If I comment out all the database code the page loads ok. There's something wrong with the connect code, however I don't see the mysql_error or exception written to the browser. Do these get logged to a file somewhere? Can anyone see a problem with the code?
The username and password are correct.
Any help is much appreciated,
Mark
here's a very simple example that uses the newer mysqli extension in conjunction with exception handling:
<?php
ob_start();
try
{
$db = new mysqli("localhost", "foo_dbo", "pass", "foo_db", 3306);
if ($db->connect_errno)
throw new exception(sprintf("Could not connect: %s", $db->connect_error));
$sqlCmd = "select * from users order by username";
$result = $db->query($sqlCmd);
if(!$result) throw new exception(sprintf("Invalid query : %s", $sqlCmd));
if($db->affected_rows <= 0){
echo "no users found !";
}
else{
$users = $result->fetch_all(MYSQLI_ASSOC);
foreach($users as $u) echo $u["username"], "<br/>";
}
$result->close();
}
catch(exception $ex)
{
ob_clean();
echo sprintf("zomg borked - %s", $ex->getMessage());
}
if(!$db->connect_errno) $db->close();
ob_end_flush();
?>
Thanks to everyone who replied - turns out that it was very 'beginners' error - mysql was not enabled in the php configuration file.
If it only outputs "here 1" that means the code stops at:
$db=mysql_connect('localhost', 'root', 'password') or die(mysql_error());
I think it is because mysql_error needs to get the last connection from mysql_connect, and the connection fails.
From the docs:
The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect() is assumed. If no such link is found, it will try to create one as if mysql_connect() was called with no arguments. If no connection is found or established, an E_WARNING level error is generated.
(emphasis mine)
http://php.net/manual/en/function.mysql-error.php
Try changing mysql_error with some string output and see if it works. If it works, then the error is in the database connection.
Try without a password: $db=mysql_connect('localhost', 'root', '') or die(mysql_error());

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