搜索多个字段MySQL

Question

I have a database like this :

ID | Name | Model | Type
1  | Car  | 4     | C
2  | Bar  | 2     | B
3  | Car  | 4     | D
4  | Car  | 3     | D

And a form like this :

Name : 
Model : 
Type :

Now, I would like to search only the name, for example "Car" and it returns lines 1, 3, 4. (I left Model and Type empty)

If I search "Car" in Name and 4 in Model, it returns lines 1, 3. (I left Type empty)

And if I search "Car" in Name and "D" in Type, it returns line 3, 4 (I left Model empty)

Is it possible to do this in one query ?

This is what I had :

SELECT *
FROM items
WHERE (:name IS NOT NULL AND name = :name)
AND (:model IS NOT NULL AND model = :model)
AND (:type IS NOT NULL AND type = :type)

But it doesn't work. I would like to fill only 2 on 3 fields and the the "WHERE" adapts and ignore the blank field.

EDIT 1 : It is a little hard to explain but I have a form. I want to have only one required field, the two others are optional but if I also fill the one other or two others fields, they act like a filter.

So the name field is required (in the form). If I fill only the name field, it will select only where name = :name. If I fill name + model, it will select where name = :name AND model = :model. and so on...

Thank you for your help.

Answer 1

I'm not sure what you mean by "blank", but assuming you mean NULL , you can do something like this:

SELECT *
FROM items
WHERE (:name IS NULL OR name = :name) AND
      (:model IS NULL OR model = :model) AND
      (:type IS NULL OR type = :type);

That problem with this query is that it is very hard for MySQL to use indexes for it, because of the or conditions. If you have a large amount of data, and want to use indexes, then you should construct the where clauses based on the parameters that actually have data.

Answer 2

Here's an alternative approach using PHP. You'll need to update the variables.

<?php
$query = 'SELECT *
FROM items
WHERE 1 = 1 ';
//below used for testing can be remove
//$_GET['name'] = 'test';
//$_GET['car'] = 'test2';
//$_GET['type'] = 'test3';
if(!empty($_GET['name'])) {
    $query .= ' and name = ? ';
    $params[] = $_GET['name'];
}
if(!empty($_GET['car'])) {
    $query .= ' and car = ? ';
    $params[] = $_GET['car'];
}
if(!empty($_GET['type'])) {
    $query .= ' and type = ? ';
    $params[] = $_GET['type'];
}
if(!empty($params)) {
    $dbh->prepare($query);
    $sth->execute($params);
    //fetch
} else {
    echo 'Missing Values';
}

The 1=1 is so you can append and search field for each field with a value otherwise you'd need to see if it'd already been set.