如何使用分隔的列和值数组生成查询

Question

I have this array:

$filter=['color*black','color*blue','color*red','paint*apex','paint*dalton'];

Each value in $filter has two substrings separated by *. The first substring represents a database table column and the second represents a desired value for that column.

My products table looks like this:

id    name    color    paint
1     p1      black     compo
2     p2      red       dalton
3     p3      pink      apex
4     p4      blue      apex
5     p5      cream     compo

Using $filter, I need to search the products table and return all rows with a paint value of apex or dalton AND a color value of black, blue, or red.

The desired output is a mysql query that will only return these rows:

id    name    color    paint
2     p2      red       dalton
4     p4      blue      apex

Answer 1

If You need to construct a query like this SELECT * FROM products WHERE (color IN ('black', 'blue', 'red')) AND (paint IN ('apex', 'dalton')), then the code below might be useful (please, check it here):

$filter = array(
    0 => "color*black",
    1 => "color*blue",
    2 => "color*red",
    3 => "paint*apex",
    4 => "paint*dalton"
);

$elements = [];

foreach ($filter as $value) {
    list($before, $after) = explode('*', $value);
    $elements[$before][] = $after;
}

$parts = [];

foreach ($elements as $column => $values) {
    $parts[] = "(`$column` IN ('" . implode("', '", $values) . "'))";
}

$query = 'SELECT * FROM `products` WHERE ' . implode(' AND ', $parts);

Running this query against the given table data structure:

id    name    color    paint
1     p1      black     compo
2     p2      red       dalton
3     p3      pink      apex
4     p4      blue      apex
5     p5      cream     compo

will match the following rows:

2     p2      red       dalton
4     p4      blue      apex