MySQL Where Clause using php

The WHERE clause is used to extract only those records that fulfill a specified condition. where clause is a part of select command . it is used to fetch data from a table . we basically use this clause to filter out our results. by using where clause we can select particular set of records based specified condition. 

Syntax:

SELECT column_name1,column_name2 FROM table_name WHERE column_name = value

PHP MySQL Where Clause Query Example

<?php  
	$host = "localhost";  
	$user = "";  
	$pass = "";  
	$dbname = "users";  
	  
	$conn = mysql_connect($host,$user,$pass) or die(mysql_error());  
	if(!$conn){  
	  die("Could not connect:".mysql_connect_error());  
	}
	// select database 
	mysql_select_db($dbname,$conn);

	$userId=2;
	$sql = "SELECT * FROM users where id=".$userId;  
	$retval=mysql_query($sql);  
	  
	if(mysql_num_rows($retval) > 0){  
		echo "<table border='1'>";
		echo "<tr><th>ID</th><th>Name</th><th>Salary</th></tr>";
		while($row= mysql_fetch_array($val))
		{
			echo "<tr>";	
			echo "<td>".$row['id']."</td>";
			echo "<td>".$row['name']."</td>";
			echo "<td>".$row['salary']."</td>";
			echo "</tr>";
		}		
		echo "</table>";
	}else{  
		echo "0 results";  
	}  
	mysql_close();  
?>

Output: Users