using WHERE clause as a variable in MySQL query not working

Question

This is really weird.

This query obviously works:

$query = mysql_query("SELECT * FROM restaurant_page WHERE title LIKE '%$search_title%'");

But, this doesn't:

$category = 'restaurant_page';

$query = mysql_query("SELECT * FROM '$category' WHERE title LIKE '%$search_title%'");

With the second query, I get the resource boolean error.

$category is table the user wants to search from. When I print out the query with the variable, it's the exact same as the first one. Why wouldn't this work?

Got is guys. Thanks. It was ticks. I was thinking INSERT VALUES. Uggg... That was dumb. — Graham
– Graham, Commented Nov 16, 2011 at 19:25

Jacob Mattison · Accepted Answer · 2011-11-16 19:20:34Z

2

Does the query created with the variable have quotes areound the table name? That seems like a mistake to me.

answered Nov 16, 2011 at 19:20

Jacob Mattison

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knittl · Accepted Answer · 2011-11-16 19:23:00Z

1

Don't use single quotes around your table name, use backticks (`) instead:

$query = mysql_query("SELECT * FROM `$category` WHERE title LIKE '%$search_title%'");

NB. Please make sure that $category and $search_title are not plain user provided variables

answered Nov 16, 2011 at 19:23

knittl

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Jonathan Kuhn · Accepted Answer · 2011-11-16 19:21:01Z

1

in the mysql query, don't put quotes around $category.

$query = mysql_query("SELECT * FROM $category WHERE title LIKE '%$search_title%'");

answered Nov 16, 2011 at 19:21

Jonathan Kuhn

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Michael Berkowski · Accepted Answer · 2011-11-16 19:21:18Z

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Remove the single quotes from '$category'.

"SELECT * FROM '$category' WHERE title LIKE '%$search_title%'"
---------------^^^^^^^^^^^^

If needed, surround $category with backticks. This is only necessary if $category contains a MySQL reserved keyword. However, since it is a variable that could become a possiblity.

$query = mysql_query("SELECT * FROM `$category` WHERE title LIKE '%$search_title%'");

Of course, please don't forget to escape $category since it may be user input. We assume you have already done so for $search_title as well.

$category = mysql_real_escape_string($category);

answered Nov 16, 2011 at 19:21

Michael Berkowski

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Grouchal · Accepted Answer · 2011-11-16 19:21:43Z

0

Why have you got quotes around $category - remove these and it should work.

answered Nov 16, 2011 at 19:21

Grouchal

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Johannes Klauß · Accepted Answer · 2011-11-16 19:22:06Z

0

You should always seperate the variables from the actual string. Do something like this:

$category = "restaurant_page";

$query = mysql_query("SELECT * FROM `".$category."` WHERE title LIKE
'%".$search_title."%'");

answered Nov 16, 2011 at 19:22

Johannes Klauß

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Leysam Rosario · Accepted Answer · 2011-11-16 19:25:44Z

0

LOL. This makes my day. remove the quote on the $category. Im sure this is just a funny mistake. All of us made some mistake. hehe

To solve this change the ' to "

$query = mysql_query("SELECT * FROM ".$category." WHERE title LIKE '%$search_title%'");

answered Nov 16, 2011 at 19:25

Leysam Rosario

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