TYPO3 selectMultipleSideBySide数据库查询

Question

Hi in TYPO3 i have following code

TCA:

'cat' => [
        'exclude' => true,
        'label' => 'LABEL',
        'config' => [
            'type' => 'select',
            'renderType' => 'selectMultipleSideBySide',
...

This saves a string in the table. If i select more than one option it saves like this in the table "1,2" (selected categorie 1 and 2). The controller has this code

Controller:

$catlist = explode(',', $categories);
    $searchForValue = ',';
    foreach ($catlist as $cat) {
        $and .= ' OR categories = ' . '"' . $cat . '"';
        if (strpos($categories, $searchForValue) !== false) {
            $where = ' WHERE categories = ' . '"' . $categories .'"' . $and;
        } else {
            $where = ' WHERE categories = ' . '"' . $categories .'"';
        }
    }

this is giving me following statement:

SELECT * FROM TABLE WHERE categories = "2,3" OR categories = "2" OR categories = "3"

But if i have an article with the categories 2 and 1 there ist the string "2,1" in the database and my query wont work. I just get the article with category 3 and not the one with 2 and 1 (2,1). How can i generate a useful query?

Answer 1

When I have this type of problem I generally execute a query with a where clause that covers all the possible cases, that are 4 (related to the data stored in the DB)

• 2 (2 is the only category of the article)
• 2, (2 is the first category of the article)
• ,2 (2 is the last category of the article)
• ,2, (2 is one category among others)

Then you have to change the controller that builds the query, so that the WHERE is in this form:

WHERE categories='2' OR categories LIKE '2,%' OR categories LIKE '%,2' OR categories LIKE '%,2,%'

Surely there is a better and more efficient way, let's see if someone else responds so we learn it.

Obviously this solves the problem when the search is done for a single category (I did not understand if your problem is this or that of searching with 2 or more categories). In the latter case you have to include all possible combinations in the where, and this greatly increases the complexity of the problem, making my solution very unsuitable.

However, if your search on multiple categories is not exclusive, ie it is enough that an article has one of the selected categories (only 2 or 3) then you can simply build the 4 combinations in OR for each category searched. This means that with 2 categories you will have 8 where clauses in OR, with 3 categories 12, with N you will have n * 4 where clauses. As mentioned, you can certainly work on something more performing, but fortunately I have never needed it to date

EDIT: thank to @GeorgRinger for the tips. Using the function FIND_IN_SET the construction of the where clause should be something like this (always if only one category match is needed)

$where = "";
foreach ($catlist as $cat) {
    if ($where!=""){
        $where = $where . " OR ";
    }
    $where = $where . " FIND_IN_SET(\"".$cat."\",categories)>0 "
}
$where = "WHERE " . $where