I have a page say pae1.php has code like
include_once('db.php');
in db.php the connection is established
$con= mysql_connect("localhost", "username", "password") or die(mysql_error());
mysql_select_db("dbname") or die(mysql_error());
I then simply run a query on page1.php as
$delete_s1ql="DELETE FROM tbl_info WHERE id='$id' ";
$res_del=mysql_query($delete_s1ql) or die(mysql_error());
Now I want to close my database connection on page1.php.
How can I do this?
Change db.php into this (to make sure the selected database is bound to the resource):
$con= mysql_connect("localhost", "username", "password") or die(mysql_error());
mysql_select_db("dbname", $con) or die(mysql_error());
In page1.php add this to the end (use the global resource-variable to close the correct connection):
mysql_close($con);
PS: take a look at PDO for a better way to connect and talk to your database.
Try this one
mysql_close($con);
MySQL extension is deprecated as of PHP 5.5.0, and is not recommended for writing new code as it will be removed in the future. Instead, either the mysqli or PDO_MySQL extension should be used.
you can simply use mysql_close($con); in pae1.php since include_once also includes the variables defined in db.php
Use PDO... Basically, try using PHP libraries for infrastructure purposes like DB
Related
I read more than once that is better to use mysqli and than mysql.
I would like to know:
I'm using WAMP for my local server and some share server for my online sites. what do i need to check on php.ini in order to be sure that mysqli will works?
below is my db connection and query code. how would it looks like using mysqli?
$con = #mysql_connect ("localhost", "username", "pass");
if(!$con)
exit("Unable to connect to the Database server");
$db2 = #mysql_select_db("DB_NAME");
if(!$db2)
exit("Unable to connect to the Database");
$query = mysql_query("SELECT somme_filed FROM some_table");
while ($index= mysql_fetch_array($query ))
{
....
}
most of my site was written in mysql. Do I really need to change all the code to mysqli? Is it really so important?
1.As long as you have only one instance of php installed there should not be any problem but if you have more than one instance you may need to point it manually to the version you wish to use. How do I activate mysqli with wampserver?
2.You can use mysqli to connect by doing something like this
$con = mysqli_connect("localhost","my_user","my_password","my_db");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
3.MYSQL is no longer under development and has been considered deprecated.
Why shouldn't I use MYSQL functions
I have a nice free for searching a database. It was written with PHP and MySql...however for whatever reason, I occasionally need to add an "i" at the end of MySql occasionally to get things working. I can connect and login, but not select the database, since it passes through until I get the
"request "Unable to select database."
Here's the meat from the config.php file that probably has the issue :
$SETTINGS["hostname"]='localhost';
$SETTINGS["mysql_user"]='root';
$SETTINGS["mysql_pass"]='root';
$SETTINGS["mysql_database"]='myDB';
$SETTINGS["data_table"]='data'; // this is the default database name that we used
/* Connect to MySQL */
if (!isset($install) or $install != '1') {
$connection = mysqli_connect($SETTINGS["hostname"], $SETTINGS["mysql_user"], $SETTINGS["mysql_pass"]) or die ('Unable to connect to MySQL server.<br ><br >Please make sure your MySQL login details are correct.');
$db = mysqli_select_db($SETTINGS["mysql_database"], $connection) or die ('request "Unable to select database."');
};
?>
The problem you are facing is the line in which you select the database;
$db = mysqli_select_db($SETTINGS["mysql_database"], $connection) or die ('request "Unable to select database."');
As defined by the documentation of mysqli_select_db() the connection $connection ($link in the docs) should be the first argument:
$db = mysqli_select_db($connection, $SETTINGS["mysql_database"]);
The reason why you need to occasionally add an i to every mysql_* function is because all mysql_* functions are officially deprecated, no longer maintained and removed in PHP 7.0.0. You should update your code with PDO or MySQLi to ensure the functionality of your project in the future.
With mysqli, you can select your database directly using the connection method :
$connection = mysqli_connect($SETTINGS["hostname"], $SETTINGS["mysql_user"], $SETTINGS["mysql_pass"], $SETTINGS["mysql_database"]);
If you want to use mysqli_select_db, you need to reverse your arguments. First the connection, then the database :
mysqli_select_db($connection, $SETTINGS["mysql_database"]);
I'm about to use mysqli instead of mysql for the first time in my procedural PHP application.
index.php
include(db_conn.php);
<html>
<body>
<?php include(content.php);?>
</body>
</html
db_conn.php
<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
content.php
mysqli_query($con,"SELECT * FROM Persons");
mysqli_query($con,"INSERT INTO Persons (FirstName,LastName,Age)
# more code...
mysqli_query necessarily requires the connection variable and my connection is stored in variable $con in the included db_conn.php file which is unavailable in another included content.php file.
Within your content.php use require(db_conn.php); And if you have a function defined in there, you're going to have to put require(db_conn.php); INSIDE that function.
The database connection doesn't seem to have exactly the same scoping as a standard variable.
I know when coding it, you feel like "I should only have to include this once!" but shrug get everything else working first, and if someone wants to pay you to go back and try to "fix" this... work on it then. ;)
I want to create a login system of my website,so I read this page
http://www.codingcage.com/2015/01/user-registration-and-login-script-using-php-mysql.html
and also I create a MySql database
and I got this message:"oops database selection problem ! -->
Access denied for user 'a9891486_UsersID'#'10.1.1.31' to database 'dbtest'"
and I know it is some thing wrong in my dbconnect.php
dbconnect.php code:
<?
if(!mysql_connect("mysql9.000webhost.com","Username","Password","dbtest"))
}
die('oops connection problem ! --> '.mysql_error());
}
if(!mysql_select_db("dbtest"))
}
die('oops database selection problem ! --> '.mysql_error());
}
?>
and I know what is "Username" and "Password"
THANK A LOT!!!!!!!!!!!!!!!!!!!
Try this:
<?
$conn = mysql_connect("mysql9.000webhost.com", "username", "password") or die(mysql_error());
//to select the targeted database
mysql_select_db("dbtest", $conn) or die(mysql_error());
?>
Just a couple of points about the code
mysql_connect accepts only 3 parameters the dbname goes in the mysql_select_db()
your if statements have incorrect bracketting
its always safer to use <?php rather than <?
Suggested code changes
<?php
if(!mysql_connect("mysql9.000webhost.com", "Username", "Password"))
{
die('oops connection problem ! --> '.mysql_error());
}
if(!mysql_select_db("dbtest"))
{
die('oops database selection problem ! --> '.mysql_error());
}
?>
But again I have to say
Please dont use the mysql_ database extensions, it is deprecated (gone for ever in PHP7)
Especially if you are just learning PHP, spend your energies learning the PDO or mysqli_ database extensions,
and here is some help to decide which to use
I am new to php syntax and am looking for advice on creating the most acceptable or correct code. I focus on front end design, but I like to make sure my code is proper. I am in a digital media program, my instructor has given us this code for connecting to our MYSQL databases.
<?php
mysql_connect("localhost", "root", "root")or die("Cannot Connect to DB");
mysql_select_db("Example")or die("cannot select the DB Example ");
?>
However when I look at connect scripts online they set the mysql_connect function as a variable lets say $connect and run an if statement stating; if not $connect produce error, and the same for mysql_select_db. They also close the script with mysql_close($connect); like below
<?php
$connect = mysql_connect("localhost", "root", "root");
if (!$connect)
{
die('Could not connect: ' . mysql_error());
}
$db_selected = mysql_select_db("Example", $connect);
if (!$db_selected)
{
die ("Can\'t use test_db : " . mysql_error());
}
mysql_close($connect);
?>
Is either one better? What problems can I have if I dont close the connect with mysql_close?
Regarding using an if instead of an or, it doesn't matter. The or short-circuits, so if the connection worked, die(...) won't be executed. Using either is a matter of preference. If you want to use the or version while keeping the result of the mysql_connect() call, simply assign the whole expression to a variable:
$connection = mysql_connect(...) or die('Connection failed.');
mysql_close() should be used after you're done with all your database communication.
The other mysql_*() functions will use the connection created by the latest call to mysql_connect() or mysql_pconnect(). If for some reason you want more than one connection, trusting the implicit connection object in this manner will fail. Better is to store the connection object yourself and passing it in wherever you need it.
Also before starting to work with databases, you should be aware that mysql is not secure anymore and is deprecated, you should use mysqli. You can use it also as object oriented language.
more details : http://www.php.net/manual/en/book.mysqli.php
example :
<?php
$con = mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
?>