如何使用 codeigniter 在数据库中搜索逗号分隔值

Question

I am trying to filter a database by having a category column, so I search for the category and the correct items are returned. However some items have more than one category so I have used comma separated values to put two or more categories in one column. I tried this method:

   public function get_cat_article($value)
    {
        $table = $this->get_table();
        $this->db->where('cat', $value);
        return $this->db->get($table);
    }

but that only picks up the first of the separated values. I tried using 'where_in' but that also picked up only the first value. I tried 'like' and that worked but was not definitive. A search for 'WS' included other categories like 'IWS'. I googled for a solution and fin_in_set was suggested so I tried:

public function get_cat_article($value)
    {
        $table = $this->get_table();
        $this->db->where('find_in_set('.$value.',cat)');
        return $this->db->get($table);
    }

But this didn't work at all. Have I got the syntax wrong or is this the wrong approach?

Answer 1

Have you tried like query? In a quick demo, this works for me.

public function get_cat_article($value)
{
    $table = $this->get_table();

    $this->db->like('cat', $value);  // say, $value = 'reebok'
    return $this->db->get($table);

    // Produces: SELECT * FROM $table WHERE `cat` LIKE '%reebok%' ESCAPE '!'
}

For more details read CodeIgniter official user guide here .

Answer 2

Try like method but this way:

public function get_cat_article($value)
{
    $table = $this->get_table();

    $this->db->like('cat', $value . ',', 'after');
    $this->db->or_like('cat', ',' . $value . ',');
    $this->db->or_like('cat', ',' . $value, 'before');
    return $this->db->get($table);
}

Answer 3

The problem appears to be solved using the following line of code using the MySql 'find_in_set' technique. I got the code from this website at Check the conditions in comma separated values and the key line is:

$this->db->where("FIND_IN_SET( '$post_period' , period) ");

I just got the syntax wrong.