php mysql_select_db parameter 2 not working - php

I have the following code for test, and I just found the 2nd parameter is not actually working.
$conn1 = mysql_connect("127.0.0.1", "xxxx", "xxxx");
$conn2 = mysql_connect("127.0.0.1", "xxxx", "xxxx");
mysql_select_db("test", $conn1);
mysql_select_db("yangshengfun", $conn2);
if (!$res = mysql_query("select * from proxy_ips limit 1", $conn1)) {
echo mysql_error($conn1);
}
if (!$res = mysql_query("select * from wp_posts limit 1", $conn2)) {
echo mysql_error($conn2);
The tables in database 'test' and 'yangshengfun' are complately different.
An error occured while I run this code:
Table 'yangshengfun.proxy_ips' doesn't exist
Seems when I call mysql_select_db for $conn2, it changes the current db of $conn1 too, any ideas?

try this
$conn1= mysql_connect("host_name", "user_name", "pass_word") or die('not connected');
mysql_select_db("database_name", $conn1);
Here the "die($message)" function prints a message if mysql_connect() function can't connect with db.

try this
$conn1 = mysql_connect("127.0.0.1", "xxxx", "xxxx", true);
$conn2 = mysql_connect("127.0.0.1", "xxxx", "xxxx", true);
Note : mysql_* is deprecated. use mysqli_* or pdo

Use mysqli instead:
<?php
$conn1 = new mysqli(host, user, password, db);
$conn2 = new mysqli(host2, user2, password2, db2);
?>

From the documentation of mysql_connect() of the PHP Manual
If a second call is made to mysql_connect() with the same arguments,
no new link will be established, but instead, the link identifier of
the already opened link will be returned. The new_link parameter
modifies this behavior and makes mysql_connect() always open a new
link, even if mysql_connect() was called before with the same
parameters. In SQL safe mode, this parameter is ignored.
This (mysql_*) extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, Prepared Statements of MySQLi or PDO_MySQL extension should be used to ward off SQL Injection attacks !

Related

probléme lors de la création d'une page de login in php [duplicate]

I am trying to do a simple connection with XAMPP and MySQL server, but whenever I try to enter data or connect to the database, I get this error.
Fatal error: Uncaught Error: Call to undefined function mysql_connect() in C:\xampp\htdocs\register.php:22
Stack trace: #0 {main} thrown in C:\xampp\htdocs\register.php on line 22
Example of line 22:
$link = mysql_connect($mysql_hostname , $mysql_username);
mysql_* functions have been removed in PHP 7.
You probably have PHP 7 in XAMPP. You now have two alternatives: MySQLi and PDO.
You can use mysqli_connect($mysql_hostname , $mysql_username) instead of mysql_connect($mysql_hostname , $mysql_username).
mysql_* functions were removed as of PHP 7. You now have two alternatives: MySQLi and PDO.
It is recommended to use either the MySQLi or PDO extensions. It is not recommended to use the old mysql extension for new development, as it was deprecated in PHP 5.5.0 and was removed in PHP 7.
PHP offers three different APIs to connect to MySQL. Below we show the APIs provided by the mysql, mysqli, and PDO extensions. Each code snippet creates a connection to a MySQL server running on "example.com" using the username "username" and the password "password". And a query is run to greet the user.
Example #1 Comparing the three MySQL APIs
<?php
// mysqli
$mysqli = new mysqli("example.com", "username", "password", "database");
$result = $mysqli->query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = $result->fetch_assoc();
echo htmlentities($row['_message']);
// PDO
$pdo = new PDO('mysql:host=example.com;dbname=database', 'username', 'password');
$statement = $pdo->query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = $statement->fetch(PDO::FETCH_ASSOC);
echo htmlentities($row['_message']);
// mysql
$c = mysql_connect("example.com", "username", "password");
mysql_select_db("database");
$result = mysql_query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = mysql_fetch_assoc($result);
echo htmlentities($row['_message']);
?>
I suggest you try out both MySQLi and PDO and find out what API design you prefer.
Read Choosing an API and Why shouldn't I use mysql_* functions in PHP?
As other answers suggest... Some guy (for whatever reason) decided that your old code should not work when you upgrade your PHP, because he knows better than you and don't care about what your code does or how simple it is for you to upgrade.
Well, if you can't upgrade your project overnight you can
downgrade your version of PHP to whatever version that worked
or...
use a shim (kind of polyfill) such as https://github.com/dshafik/php7-mysql-shim or https://github.com/dotpointer/mysql-shim, and then find a place for include_once("choice_shim.php"); somewhere in your code
That will keep your old PHP code up and running until you are in a mood to update...
mysql_* functions have been removed in PHP 7.
You now have two alternatives: MySQLi and PDO.
The following is a before (-) and after (+) comparison of a migration to the MySQLi alternative, taken straight out of working code:
-if (!$dbLink = mysql_connect($dbHost, $dbUser, $dbPass))
+if (!$dbLink = mysqli_connect($dbHost, $dbUser, $dbPass))
-if (!mysql_select_db($dbName, $dbLink))
+if (!mysqli_select_db($dbLink, $dbName))
-if (!$result = mysql_query($query, $dbLink)) {
+if (!$result = mysqli_query($dbLink, $query)) {
-if (mysql_num_rows($result) > 0) {
+if (mysqli_num_rows($result) > 0) {
-while ($row = mysql_fetch_array( $result, MYSQL_ASSOC )) {
+while ($row = mysqli_fetch_array( $result, MYSQLI_ASSOC )) {
-mysql_close($dbLink);
+mysqli_close($dbLink);
mysql_ functions have been removed from PHP 7. You can now use MySQLi or PDO.
MySQLi example:
mysqli_connect($mysql_hostname, $mysql_username, $mysql_password, $mysql_dbname);
mysqli_connect reference link
Make sure you have not committed a typo as in my case
msyql_fetch_assoc should be mysql
For mysqli you can use :
$db = ADONewConnection('mysqli');
...
...
$db->execute("set names 'utf8'");
in case of a similar issue when I'm creating dockerfile I faced the same scenario:-
I used below changed in mysql_connect function as:-
if($CONN = #mysqli_connect($DBHOST, $DBUSER, $DBPASS)){
//mysql_query("SET CHARACTER SET 'gbk'", $CONN);

Migrating to PHP7.x, Deprecated functions

So here's the problem, the script I purchase is written on PHP 5.x, and I'm using xampp with PHP7.x installed for development. Now I want to migrate my script to PHP7.x. Now I know this was asked a million times already but do you mind if you could take a look at my code and give your thoughts about it, or simply share your knowledge. I would deeply appreciate it.
Here is the code for my config.php
<?php
// mySQL information
$server = 'localhost'; // MySql server
$username = 'admin'; // MySql Username
$password = 'admin' ; // MySql Password
$database = 'arcade'; // MySql Database
// The following should not be edited
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);
$con = mysql_connect($server, $username, $password);
if (!$con)
{
die('Could not connect: ' . mysql_error());
}
mysql_select_db($database, $con);
// Get settings
if (!isset($install)) {
$sql = mysql_query("SELECT * FROM ava_settings");
while ($get_setting = mysql_fetch_array($sql)) {
$setting[$get_setting['name']] = $get_setting['value'];
}
}
?>
The deprecated functions are:
mysql_connect()
mysql_error()
mysql_fetch_array()
mysql_query()
mysql_select_db()
Now, I don't want to use the PDO approach, I want to use mysqli instead. Am I suppose to just replace the mysql_* into mysqli_*? So it will become like these? I don't want to hide/surpress the deprecate warnings.
mysqli_connect()
mysqli_error()
mysqli_fetch_array()
mysqli_query()
mysqli_select_db()
I just offer you that migrate to PDO driver. Because every update you may see a lot of deprecation errors.
But if you can not do it the first thing to do would probably be to replace every mysql_* function call with its equivalent mysqli_*, at least if you are willing to use the procedural API -- which would be the easier way, considering you already have some code based on the MySQL API, which is a procedural one.
Note that, for some functions, you may need to check the parameters carefully: Maybe there are some differences here and there -- but not that many, I'd say: both mysql and mysqli are based on the same library (libmysql ; at least for PHP <= 5.2)
Look at difference between mysqli and mysql:
$mysqli = mysqli_connect("example.com", "user", "password", "database");
$res = mysqli_query($mysqli, "SELECT ...");
$row = mysqli_fetch_assoc($res);
echo $row['_msg'];
$mysql = mysql_connect("example.com", "user", "password");
mysql_select_db("test");
$res = mysql_query("SELECT ...", $mysql);
$row = mysql_fetch_assoc($res);
echo $row['_msg'];

Fatal error: Uncaught Error: Call to undefined function mysql_connect()

I am trying to do a simple connection with XAMPP and MySQL server, but whenever I try to enter data or connect to the database, I get this error.
Fatal error: Uncaught Error: Call to undefined function mysql_connect() in C:\xampp\htdocs\register.php:22
Stack trace: #0 {main} thrown in C:\xampp\htdocs\register.php on line 22
Example of line 22:
$link = mysql_connect($mysql_hostname , $mysql_username);
mysql_* functions have been removed in PHP 7.
You probably have PHP 7 in XAMPP. You now have two alternatives: MySQLi and PDO.
You can use mysqli_connect($mysql_hostname , $mysql_username) instead of mysql_connect($mysql_hostname , $mysql_username).
mysql_* functions were removed as of PHP 7. You now have two alternatives: MySQLi and PDO.
It is recommended to use either the MySQLi or PDO extensions. It is not recommended to use the old mysql extension for new development, as it was deprecated in PHP 5.5.0 and was removed in PHP 7.
PHP offers three different APIs to connect to MySQL. Below we show the APIs provided by the mysql, mysqli, and PDO extensions. Each code snippet creates a connection to a MySQL server running on "example.com" using the username "username" and the password "password". And a query is run to greet the user.
Example #1 Comparing the three MySQL APIs
<?php
// mysqli
$mysqli = new mysqli("example.com", "username", "password", "database");
$result = $mysqli->query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = $result->fetch_assoc();
echo htmlentities($row['_message']);
// PDO
$pdo = new PDO('mysql:host=example.com;dbname=database', 'username', 'password');
$statement = $pdo->query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = $statement->fetch(PDO::FETCH_ASSOC);
echo htmlentities($row['_message']);
// mysql
$c = mysql_connect("example.com", "username", "password");
mysql_select_db("database");
$result = mysql_query("SELECT 'Hello, dear MySQL user!' AS _message FROM DUAL");
$row = mysql_fetch_assoc($result);
echo htmlentities($row['_message']);
?>
I suggest you try out both MySQLi and PDO and find out what API design you prefer.
Read Choosing an API and Why shouldn't I use mysql_* functions in PHP?
As other answers suggest... Some guy (for whatever reason) decided that your old code should not work when you upgrade your PHP, because he knows better than you and don't care about what your code does or how simple it is for you to upgrade.
Well, if you can't upgrade your project overnight you can
downgrade your version of PHP to whatever version that worked
or...
use a shim (kind of polyfill) such as https://github.com/dshafik/php7-mysql-shim or https://github.com/dotpointer/mysql-shim, and then find a place for include_once("choice_shim.php"); somewhere in your code
That will keep your old PHP code up and running until you are in a mood to update...
mysql_* functions have been removed in PHP 7.
You now have two alternatives: MySQLi and PDO.
The following is a before (-) and after (+) comparison of a migration to the MySQLi alternative, taken straight out of working code:
-if (!$dbLink = mysql_connect($dbHost, $dbUser, $dbPass))
+if (!$dbLink = mysqli_connect($dbHost, $dbUser, $dbPass))
-if (!mysql_select_db($dbName, $dbLink))
+if (!mysqli_select_db($dbLink, $dbName))
-if (!$result = mysql_query($query, $dbLink)) {
+if (!$result = mysqli_query($dbLink, $query)) {
-if (mysql_num_rows($result) > 0) {
+if (mysqli_num_rows($result) > 0) {
-while ($row = mysql_fetch_array( $result, MYSQL_ASSOC )) {
+while ($row = mysqli_fetch_array( $result, MYSQLI_ASSOC )) {
-mysql_close($dbLink);
+mysqli_close($dbLink);
mysql_ functions have been removed from PHP 7. You can now use MySQLi or PDO.
MySQLi example:
mysqli_connect($mysql_hostname, $mysql_username, $mysql_password, $mysql_dbname);
mysqli_connect reference link
Make sure you have not committed a typo as in my case
msyql_fetch_assoc should be mysql
For mysqli you can use :
$db = ADONewConnection('mysqli');
...
...
$db->execute("set names 'utf8'");
in case of a similar issue when I'm creating dockerfile I faced the same scenario:-
I used below changed in mysql_connect function as:-
if($CONN = #mysqli_connect($DBHOST, $DBUSER, $DBPASS)){
//mysql_query("SET CHARACTER SET 'gbk'", $CONN);

PHP - Selecting database from MySQL doesn't work

I have read a lot about this but it still doesn't work.
I'm just trying to select a database to create a new table in, I try:
$db = mysqli_select_db("test");
if(!$db) {
echo "error: " . mysqli_error($db);
}
But I still get an error (and mysqli_error($db) doesn't seem to work).
Of course I have already connected to it:
$con=mysqli_connect("localhost", "administrator", "****");
On phpMyAdmin I have these databases:
Why can't I select "test" ?
And creating a database doesn't work because I don't have the rights, as you can see.
The procedular signature of this function is:
bool mysqli_select_db ( mysqli $link , string $dbname )
So you will have to provide the resource you got back from the mysqli_connect() to make it work. Something like this:
$con = mysqli_connect("localhost", "administrator", "****");
$success = mysqli_select_db($con, "test");
Alternatively you could specify the database on the connect call with a 4th argument:
$con = mysqli_connect("localhost", "administrator", "***", "test");
See the examples on mysqli_connect().
mysqli_select_db function requires two parameters link and dbname. Please refer to the documentation:
http://php.net/manual/en/mysqli.select-db.php
You are only passing link and no database name in your call:
$db = mysqli_select_db("test");

PHP Data Base Connection help with mysql

i am new in php and want to know the code for php mysql database connection code
Refer to the PHP documentation for mysql_connect.
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
echo 'Connected successfully';
mysql_close($link);
Here is the bare bone of it:
$db1 = mysql_connect( ... );
mysql_select_db('existing_db',$db1);
$db2 = mysql_connect( ... );
mysql_select_db('not_existing_db', $db2);
mysql_query(... , $db2);
More Info:
http://php.net/manual/en/function.mysql-connect.php
MySQL PHP Connect Tutorial
A Detailed Tutorial:
http://www.phpf1.com/tutorial/php-mysql-tutorial.html?page=1
<?php
mysql_connect("localhost", "username", "password") or die(mysql_error());
echo "Connection to the server was successful!<br/>";
mysql_select_db("test") or die(mysql_error());
echo "Database was selected!<br/>";
?>
Watch also mysqli,it's the "new way" of connecting to mysql
http://php.net/manual/en/book.mysqli.php
it has more functions and there are rumors that in php6 mysql will be deprecated for the mysqli implementation.
you can use it as an object(but if you're new also to OO it may be a little more difficult to understand)like this:
//--connection to the database--
$db=mysqli_connect('sql.mysqlhost.com','database_username','password','database_name');//you can also use $db=new mysqli(....) but mysql_connect does the same thing and it's more cler on what it's doing
//--a simple query--
if($result=$db::query('SELECT name,value FROM mytable')){//query ok
echo 'Select returned ',$result->num_rows,'rows<br/>';
while($row=$result->fetch_assoc()){//get one row in an assoc.array
echo 'Name:',$row['name'],' Value:',$row['value'],'<br/>';//print each row
}
$result->close();
}
else//query error
die('MYSQL ERROR:'.$db->error);
or with functions like in mysql
//--connection to the database--
$db=mysqli_connect('sql.mysqlhost.com','database_username','password','database_name');
//--a simple query--
if($result=mysql_query($db,'SELECT name,value FROM mytable')){//query ok
echo 'Select returned ',mysql_num_rows($result),'rows<br/>';
while($row=mysqli_fetch_assoc($result)){//get one row in an assoc.array
echo 'Name:',$row['name'],' Value:',$row['value'],'<br/>';//print each row
}
mysql_free_result($result);
}
else//query error
die('MYSQL ERROR:'.mysqli_connect_error());
You can also use a persistent mysql connection prepending 'p:' to the sql host,for example if your host is sql.myhost.com:
$db=mysqli_connect('p:sql.mysqlhost.com','database_username','password','database_name');
Using a persistent connection should give you a great performance boost and mysqli should handle the persistent connection a lot better than the normal mysql extension.
Remember to sanitize the input of your query to avoid SQL INJECTION,you can do like this:
$result=mysql_query($db,"SELECT name,value FROM mytable where name='".mysqli_real_escape_string($input_name)."'");
or using a prepared statement that's a little more complicated and it's better only if you repeat the same command multiple times only changing the input data.

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