Question

I have two tables in one database.

id | title
---------           // table name is tableone
1  |  a
2  |  b
3  |  c
4  |  d
5  |  a
6  |  b
7  |  c
8  |  d

for the first table the primary key is the ID column. from this table I am using PHP to create a HTML table which works fine.

The second table

id | version
---------
a  |  1
b  |  3
c  |  6
d  |  7

in the while loop for the first table I have predefined the title value as

$title = $id['title'];

within the while loop i am using another while loop yet this time I am trying to use the predefined title to access the matching id’s corresponding version row value on the second table using :

mysql_query("SELECT version FROM tableone WHERE ID=".$title)

however i am hinted with the error

Unknown column ‘a’ in ‘where clause’

what is the problem and how can i fix it ?

Answer 1

You should must enclose the $title in quotes like this:

mysql_query("SELECT version FROM tableone WHERE ID='".$title."'")

If you have user supplied input, you should make sure that your code is secure for all cases.

In this post are some good informations about that: https://stackoverflow.com/questions/3714107/php-mysql-security-checklist-the-definitive-practical-guide