在我的HTML select标签中添加一个“全部”选项

Question

So I'm on my way to completing my website. However I was wondering, how can I structure my SQL statement so when I click the submit button with an option having "all" I get all the results in that field with the addition of the other criteria. If you know any good tutorials could you please recommend one.

<select name="make" id ="make" size="0">
    <option selected ="all">All</option>
    <option value="bmw">BMW</option>
    <option value="honda">Honda</option>
    <option value ="nissan">Nissan</option>
    <option value="toyota">Toyota</option>
</select>

$sql = sprintf("SELECT * FROM  `chjadb_vehicles` WHERE  `v_make` LIKE '$make');

Answer 1

Here's one approach that only requires changing the SQL:

SELECT *
FROM chjadb_vehicles
WHERE (v_make = '$make' OR '$make' = 'all')

The parentheses are not strictly necessary here but I added them anyway in case you later decide to add another AND ... condition.