How to join two tables in mysql?

<?php
// Simple Join Query
mysql_connect("localhost", "root", "pass") or die(mysql_error());
mysql_select_db("dbname") or die(mysql_error());

$query = "SELECT emp.empname, empdesig.designation FROM emp, empdesig WHERE emp.empname = empdesig.empname";
   
$result = mysql_query($query) or die(mysql_error());

//display record empname with designation.

while($rec = mysql_fetch_array($result))
   {
    echo $rec['empname']. " :- ". $rec['designation']."<br>";
    }
?>

How to update table records and displaying in sorting order.

<?php
mysql_connect("localhost", "root", "pass") or die(mysql_error());
mysql_select_db("dbname") or die(mysql_error());

//update Query
$result = mysql_query("UPDATE emp SET fieldname='robin' WHERE fieldname='rock'")
or die(mysql_error()); 

$result = mysql_query("SELECT * FROM emp WHERE fieldname='robin'") or die(mysql_error()); 

$row = mysql_fetch_array( $result );
echo $row['fieldname']." - ".$row['age'];

//Delete Query

mysql_query("DELETE FROM emp WHERE fieldname='robin'") or die(mysql_error());

//Order By [sorting ASC] Query

$result = mysql_query("SELECT * FROM emp WHERE fieldname='robin' order by fieldname ASC") or die(mysql_error()); 

//Order By [sorting DESC] Query

$result = mysql_query("SELECT * FROM emp WHERE fieldname='robin' ORDER BY fieldname DESC") or die(mysql_error()); 


//Group by Query

$query = mysql_query("SELECT fieldname, MIN(age) FROM emp GROUP BY fieldname") or die(mysql_error());

?>

How to create a table and insert records and retrieve data?

<?php
// mysql Connection
mysql_connect("localhost", "root", "pass") or die(mysql_error());
mysql_select_db("dbname") or die(mysql_error());

//emp table create
mysql_query("CREATE TABLE emp(id INT NOT NULL AUTO_INCREMENT,PRIMARY KEY(id),empname VARCHAR(30), empid INT)") or die(mysql_error());

//insert records to emp table
mysql_query("INSERT INTO emp (empname, empid) VALUES('melvin', '101' ) ") or die(mysql_error());

mysql_query("INSERT INTO emp (empname, empid) VALUES('rudie', '102' ) ")  or die(mysql_error());

// get data
$result = mysql_query("SELECT * FROM emp")or die(mysql_error());
$rec = mysql_fetch_array( $result );

// print the result
echo "empname: ".$rec['empname'];
echo "empid: ".$rec['empid'];
?>

How to get database Table structure detail ?

<?php
$db="dbname";
$username="root";
$password="";
$host="localhost";

$connection = @mysql_connect($host,$username,$password,false,2) or die("Unable to connect Mysql server");
@mysql_select_db($db,$connection) or die ("unable to connect Database");

$result = mysql_query('select * from orders');
if (!$result) {
    die('Query failed: ' . mysql_error());
}
/* get table column data */
$i = 0;
while ($i < mysql_num_fields($result))
{

echo "Information for column $i:<br />\n";
$data = mysql_fetch_field($result, $i);
if (!$data) {
echo "No information available<br />\n";
}
echo "<pre>
blob:         $data->blob
max_length:   $data->max_length
multiple_key: $data->multiple_key
name:         $data->name
not_null:     $data->not_null
numeric:      $data->numeric
primary_key:  $data->primary_key
table:        $data->table
type:         $data->type
unique_key:   $data->unique_key
unsigned:     $data->unsigned
zerofill:     $data->zerofill
</pre>";
$i++;
   }
mysql_free_result($result);
?>


Result
-----------


Information for column 0:

blob:         0
max_length:   2
multiple_key: 0
name:         orders_id
not_null:     1
numeric:      1
primary_key:  1
table:        orders
type:         int
unique_key:   0
unsigned:     0
zerofill:     0

.

.

.

.

.

Information for column 10:

blob:         0
max_length:   2
multiple_key: 0
name:         order_name
not_null:     1
numeric:      1
primary_key:  0
table:        orders
type:         string
unique_key:   0
unsigned:     0
zerofill:     0

How to connect mysql database in PHP?

<?php
$server="localhost";
$dbname="mydb";
$username="root";
$password="";

$connection=mysql_connect($server,$username,$password);

if(!$connection)
{
die("couldnot connected:".mysql_error());
}
if(mysql_query("create database mydb",$connection))
{
echo "database created";
}
else
{
echo die("database create faild".mysql_error());
}
?>