Can PHP be inserted into a SQL query?

[dalton]

Hi, I have one form containing 4 drop down boxes representing 4 table columns each of which contains a list of possible values that I am trying to pass to an SQL query on the next page. What is the best way to do this since not all 4 values may be selected before someone submits the form? I tried the following but it is not working:

$result = mysql_query("SELECT * FROM producttable WHERE <?php if ($uniques != "") { echo "uniques >= $uniques AND"; } ?><?php if ($product1cost != "") { echo "product1cost <= $product1cost AND"; } ?><?php if ($product2cost != "") { echo "product2cost <= $product2cost AND"; } ?><?php if ($product3cost != "") { echo "product3cost <= $product3cost AND"; } ?> ORDER BY category",$db);

Can I even add PHP in a SQL query? If not, can anyone provide an example of how I can dynamically generate this SQL query? Thanks in advance for any help!

[[deleted]]

Ofcourse this is not working, you can't include PHP blocks inside PHP blocks.

What you want to end up with is a single string containing the SQL query.
This does not mean you have to create the string all at once, you can create a string and append to it later, like this:

$query="SELECT * FROM table WHERE 1=1 ";
if ($something=$something_else)
{
$query .= " AND something=sometheing else";
};

$query .= " ORDER BY nothing";

echo $query;

Notice how you can use an IF statement to conditionally add text to your query.

Also notice that I have put a "WHERE 1=1" as the first condition in the statement.
"Where 1=1" is ofcourse allways true. It is only in there so I can use "AND" for the rest of my conditions. Otherwise, I'd have to put extra code in each IF statement to check if it should put WHERE or AND. This way it's allways AND.

And finally, note the use of spaces before each added statement!

[dalton]

Thank you for the reply. The info and example you provided helped alot and works great. As you can probably tell I am new to programming and php in particular so I appreciate you taking the time to assist.