Connecting to MYSQL using php - php

Question

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')";
?>

Answer 1

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.

Answer 2

"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

Answer 3

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

Answer 4

u are not executing that query.u are only declaring that query.
for execution do--
$conn->query($qry);
it will,execute ur query.