MySQL Error : Unknown column 'id' in 'where clause' error in PHP

Sometime you get MySQL Error like

Error Number: 1052

Column 'id' in order clause is ambiguous

This is just because of some misunderstanding about MySQL queries. This error occurs, when you try to search same column, which exists in two tables. For it, you need to write proper query that you can use in MySQL.
Try to follow some rules........

1. When you write any query, must sure that you have checked that in PHPMyAdmin > SQL
2. If you need to use variables in MySQL query, Try to use concatenation for that variable like:

    $query = "select * from users where name = " . $username[2];  
   

3. Try to avoid special characters in MySQL query.
4. Try to use updated PHP5.5.x functions. 
5. Make sure that your order sequence is correct.
6. Again must check that every query is working correct in Local Host.
7. Try to take attention on "Order by", "Limit", "Rand", "Atoms" functions
8. Use mysql_real_escape_string() function with variables to avoid hacking.